Mid-Month Mindbender

March 15, 2019
Divya Chandrasekharan

Identify the disorder in the riddle below.

I was born in the land of the rising sun
Aberrant notch that fires the gun
Hyperpigmented macules that darken with time
I can even escape a crime
Pigment cells in the basal layer
Yet no spill creates a fear

Email your answer to dermatopathologysocietyofindia@gmail.com. The correct answer will be available here on March 22.

February 15, 2019
Divya Chandrasekharan

Identify the disorder in the riddle below.

The mouse’s favourite meal
Fed by the master’s zeal
The lesion has a rubbery feel
Pain becomes a big deal
Look deep in the section
Lest you miss this condition
Normal architecture of fat cells fall
With chronic inflammatory cells, lipid laden macrophages in the wall!

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Sclerosing lipogranuloma (paraffinoma)

Sclerosing lipogranuloma (paraffinoma) is a specific type of factitial panniculitis. Clinically, it presents as a painful rubbery indurated lesion, resulting from the injection paraffin into subcutaneous tissue (master’s zeal). Histopathologically, it is characterized by swiss-cheese appearance. There is disruption of fat cells and their replacement by cystic spaces of variable size, some surrounded by attenuated foreign body giant cells containing lipid vacuoles. There are bands of hyaline fibrous tissue between the fat cysts. The septa contain a scattering of lymphocytes and lipid-containing macrophages and foreign body giant cells.


January 15, 2019
Divya Chandrasekharan

Identify the disorder in the riddle below.

Giant ringworms that makes you fear,
Solar rays get in gear
Mimics tuberculoid leprosy
Necrobiosis and granuloma is all that you see
As it erupts on exposed sites,
Pruritus and irritation is what patient fights
Usually seen in blacks,
Note that mucin and central zone elastic tissue it lacks!

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Granuloma multiforme

Granuloma multiforme was first distinguished from tuberculoid leprosy by Leiker et al. It is also known as Unono enyl (=elephant ringworms) in Africa. The sun exposed sites of upper trunk and arms are mainly involved. Lesions begin as papules with pruritus and irritation and evolve into annular plaques with central clearing. Histology shows foci of necrobiosis surrounded by a granulomatous zone with elastotic material within the granulomas. Unlike granuloma annulare, granuloma multiforme shows dense perivascular infiltrates and absence of mucin, and absent palisading of cells. Annular elastolytic giant cell granuloma closely resembles granuloma multiforme. It is also known as actinic granuloma/ O’Brien’s granuloma. Unlike granuloma multiforme, actinic granuloma has many multinucleated giant cells and lacks necrobiosis.

December 15, 2018
Riti Bhatia

Spot the odd one out among the following disorders on the basis of histopathological findings:
ILVEN, actinic keratoses, linear EHK, and nevus sebaceous

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Nevus sebaceous

The unifying feature in the three disorders, except nevus sebaceous, is the alternating pattern of epidermal findings. Actinic keratosis shows alternating pattern of parakeratosis due to sparing of follicular structures. Linear EHK and ILVEN show an alternating pattern of the underlying disease. This alternating pattern of underlying disease has also been found in blaschkoid VEN, linear psoriasis, and hyperpigmentary blaschkoid disorders.
Reference: Gupta V, Khandpur S, Arava S, Ramam M. Alternating histopathologic pattern in blaschkoid dermatoses with epidermal changes: A retrospective series of 61 cases. J Am Acad Dermatol 2018;78:812-3. .

Another histopathological feature that separates the other three entities from nevus sebaceous is epidermolytic hyperkeratosis. Epidermolytic hyperkeratosis is a histopathologic pattern that is seen in many conditions including linear EHK, ichthyosis bullosa of Siemens, epidermolytic keratoderma, epidermolytic acanthoma, and epidermolytic leukoplakia. It may also represent an incidental finding in ILVEN, seborrheic keratosis, actinic keratosis, in situ squamous cell carcinoma, invasive squamous cell carcinoma, melanocytic nevi, and epidermal and pilar cysts.
Metze D. Disorders of keratinization. In: Calonje E, Granter SR, Mckee PH (eds). Mckee’s Pathology of the skin. 4th ed, Elsevier Saunders 2005: 1146–96.
Meibodi NT, Nahidi Y, Javidi Z. Epidermolytic hyperkeratosis in inflammatory linear verrucous epidermal nevus. Indian J Dermatol 2011; 56: 309–12.

November 15, 2018
Riti Bhatia

Identify the disorder in the riddle below.

First described by a Hungarian dermatologist,
The names of this disease are too many to enlist.
The dilemma is not just historical,
But also clinical and histopathological.
Reticulate plaques and seborrheic dermatitis,
Histopathologically mimics classical interface dermatitis.
Renal disease and lymphoid neoplasm may develop in a few,
Look for deeper infiltrates and plasma cells for a clue.

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Nekam’s disease/ keratosis lichenoides chronica

Keratosis lichenoides chronica is a rare disease. It has often been a subject of controversy. It was first described as ‘lichen ruber moniliformis’ by Moritz Kaposi, a Hungarian dermatologist. Subsequently, it has been described as lichen ruber acuminatus, lichen ruber planus, porokeratosis striata lichenoides, and lichenoid trikeratosis. It is characterized by violaceous, papular, and nodular lesions in a linear and reticulate pattern on the extremities and a seborrheic dermatitis-like facial eruption. A rare vascular variant with telangiectasias has been reported. Oral ulceration and nail involvement may occur.
Keratosis lichenoides chronica may be associated with internal diseases such as glomerulonephritis, hypothyroidism, and lymphoproliferative disorders. Histopathologically, there is a lichenoid reaction pattern with prominent basal cell death and focal basal vacuolar change. The inflammatory infiltrate usually includes plasma cells, and there is deeper perivascular and periappendageal cuffing. Telangiectasia of superficial dermal vessels is sometimes noted. Epidermal changes are variable, with alternating areas of atrophy and acanthosis sometimes present, as well as focal parakeratosis.


October 15, 2018
Riti Bhatia

Identify the disorder in the riddle:

Itchy benign intertriginous eruption,
Equally fascinating is the reaction pattern.
Look for clues in the dead layer,
You may find something which should not be there.
Sweat, diaper or some unknown effect,
Many share an atopic gene defect.

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Granular parakeratosis

Granular parakeratosis is a unique epidermal reaction pattern reflecting an acquired disorder of keratinization, which may occur as a contact reaction to an antiperspirant, diaper or due to some unknown trigger. It is often restricted to intertriginous areas. Studies on granular parakeratosis have suggested a basic defect in the processing of profilaggrin to filaggrin which results in failure to degrade keratohyalin granules and to aggregate keratin filaments during cornification. Filaggrin mutations are known to be involved in the pathogenesis of ichthyosis vulgaris and atopic disorders.
Histopathologically, granular parakeratosis shows thickened stratum corneum with retention of keratohyalin granules. These granules are not seen beyond stratum granulosum in normal epidermis. Granular parakeratosis has been observed as an incidental finding overlying molluscum contagiosum, dermatomyositis, dermatophyte infection, and cutaneous carcinomas.

September 15, 2018
Riti Bhatia

Identify the histopathological pattern in the riddle:
Chronic itchy papules or circinate plaque,
In this histopathological subset, age is no bar.
The disorder in Japanese is not new,
When in immunosuppressed, this is a clue.
Dense infiltrate of lymphocytes, eosinophils and mast cell,
When in sebaceous glands, does it ring a bell?

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Eosinophilic pustular folliculitis

Eosinophilic pustular folliculitis is a heterogeneous group of disorders, consisting of the classic form, eosinophilic pustular folliculitis or Ofuji's disease, HIV-associated eosinophilic pustular folliculitis and pediatric eosinophilic pustular folliculitis.
The classic form, eosinophilic pustular folliculitis or Ofuji's disease, is a rare, chronic dermatosis, first described in the Japanese. It is characterised by recurrent, sterile, follicular papules and pustules with a tendency to form circinate plaques. These may show central clearing with residual hyperpigmentation. Seborrheic areas, such as the face, trunk, and extensor surface of the proximal part of the limbs, are usually involved, but in 20% of cases the non-hair-bearing palms and soles may also be involved.
HIV-associated eosinophilic pustular folliculitis has been regarded as a subset of the pruritic papular eruption of HIV infection. It differs from the classic form by severe pruritus, the absence of circinate and palmoplantar lesions, and the less frequent involvement of the face.
Pediatric eosinophilic pustular folliculitis is usually confined to the scalp, although grouped aggregates of follicular pustules can occur on the face, extremities, and trunk in some patients. It usually has a self-limited course. The inclusion of this disorder in the group of eosinophilic pustular folliculitis has been debated because interfollicular inflammation is sometimes the predominant feature.
Histopathologically, there is eosinophilic spongiosis and pustulosis involving the infundibular region of the hair follicle. The infiltrate often extends into the attached sebaceous duct and sebaceous gland. Most follicles are preserved, but some show disruption or destruction of the wall by the inflammatory infiltrate. There is also a moderately dense, perivascular and perifollicular inflammatory cell infiltrate composed of lymphocytes, eosinophils, mast cells, and macrophages.

August 15, 2018
Riti Bhatia

Single pink nodule often on the face,
That can grow with a rapid pace.
Time of stagnation will frequently come,
'Self-healing malignancy' is just a pun.
Proliferating large cells with pinkish hue,
Infiltration with 'pink' cells gives a cue.
It can proliferate in and out,
Look at the centre to shed your doubt.
One may ‘overcall’ or ‘undercall’,
Clue lies in the way this tumor will evolve.

Spot the diagnosis in the riddle.

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Keratoacanthoma was first described in 1889 by Sir Jonathan Hutchinson, as ‘crateriform ulcer of the face’. Several other terms, including ‘molluscum sebaceum’ and ‘self-healing squamous cell carcinoma’, have been applied since then. Keratoacanthoma usually presents as a solitary, pink dome-shaped nodule with a central keratin plug developing on the sun-exposed skin of elderly persons. It grows rapidly to a size of 1–2 cm over a period of 2–10 weeks. This is followed by a stationary period of similar duration. It has a tendency to involute spontaneously; this takes 8–50 weeks. The duration of the lesion is more variable than is generally recognized, and lesions may persist for over a year without involuting. Clinicians frequently discount the possibility of the lesion being a keratoacanthoma in persistent cases. Healed keratoacanthomas may leave a crateriform scar.
Keratoacanthomas are exoendophytic lesions with an invaginating mass of keratinizing, well-differentiated squamous epithelium at the sides and bottom of the lesion. There is a central keratin-filled crater which enlarges with the maturation and evolution of the lesion. Another key feature is the buttressing of the edges of the lesion which overlap the central crater, giving it a symmetrical appearance.
A well-formed crater containing keratin is present in most regressing (involuting) lesions. The component cells have a distinctive eosinophilic hue to their cytoplasm and, as they mature, toward the center of the islands of squamous epithelium, they can become quite large. Eosinophils and neutrophils may be prominent in adjacent dermis, and these may extend into the epithelial nests to form small microabscesses.

July 15, 2018
Meenakshi Batrani

Spot the disorder in the riddle:
I was born bright red, but I have grown up to have dry horn and torn hair
I always carry golf-tee and a ball
I keep sneezing in the hall
Guess the name if you can recall

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Netherton’s syndrome

It is a rare autosomal recessive disease characterized by the triad of ichthyosis, trichorrhexis invaginata (bamboo hair), and an atopic diathesis with elevated levels of IgE. Affected neonates are born with ichthyosiform erythroderma, which becomes milder with age and develop into polycyclic ichthyosis or ichthyosis linearis circumflexa. There is a characteristic hair shaft anomaly i.e. trichorrhexis invaginata (bamboo hair) where cup-like expansion of the proximal part of the hair shaft surrounds the club-shaped distal segment in the manner of a ball-and-socket joint. Because of atopic diathesis hay fever and asthma are common in affected individuals.

June 15, 2018
Riti Bhatia

Papules, pustules and crateriform exudative plaques
With neutrophilic microabscesses and epidermal hyperplasia as hallmarks
Medications, environment and diet are all to blame
Sherlockian history should be the aim
Tumor and infection may be what you think
Pause and ask for what they drink
Although many presidents’ favourite
Stop this drink and see the lesions abate

What's your diagnosis?

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Halogenoderma is characterized by eruption of papules, pustules and crateriform exudative plaques in a generalised distribution. Skin biopsy shows pseudoepitheliomatous hyperplasia with neutrophilic microabscesses, raising suspicion of keratoacanthoma and infection. Pus cultures are negative. It is caused by hypersensitivity to iodides and bromides, found in certain bromine containing drugs such as iptratropium bromide. Excessive consumption of a soft drink containing brominated vegetable oil was reported to be the cause in some patients. Although brominated vegetable oil is now banned from cola beverages, it is still a component of diet coke (a favourite drink of US presidents!). Hence taking this history is crucial as discontinuation leads to spontaneous resolution.

Source: James WD, Berger TG, Elston DM (eds). Contact dermatitis and drug reactions. Andrews' Diseases of the Skin: Clinical Dermatology. Saunders. 2016;132-3.

May 15, 2018
Vishal Gupta

Spot the odd one out:

Granuloma faciale
Rosai-Dorfman disease
Kimura’s disease
Erythema elevatum diutinum

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Erythema elevatum diutinum

Granuloma faciale, Kimura’s disease and Rosai-Dorfman disease show IgG4 positive plasma cells in skin biopsy, while erythema elevatum diutinum shows IgG4-negative plasma cells.

IgG4 related disease is a polymorphic group of inflammatory pseudotumors formed by IgG4 specific plasma cells. Granuloma faciale shows significant overlap and can be difficult to dintinguish from IgG4 related disease. Kimura’s disease shows overlapping features of inflammatory nodules with IgG4 positive plasma cells, but is distinct from this group. Tissue and peripheral eosinophilia, reactive vascular proliferation, expression of IgE in follicular dendritic cells and eosinophilic microabscesses are features of Kimura’s disease, and not IgG4 related disease. Rosai-Dorfman disease shows IgG4 positive plasma cells. However it is unrelated to IgG4 related diseases. S100 positive histiocytes are seen in the former only.

Diagnostic criteria for IgG4 related disease are: 1) clinical examination shows characteristic diffuse/ localized swelling/ masses in single or multiple organs, 2) haematological examination shows elevated serum IgG4 (135 mg/dL), 3) histopathologically, there is a) marked lymphocyte and plasma cell infiltration and fibrosis, and b) IgG4/IgG positive cells>40% and >10 igG4 positive plasma cells/ high power field. All 3 criteria are needed for definite diagnosis, 1 and 3 for probable diagnosis and 1 and 2 for possible diagnosis. Eosinophilic infiltrates are described in all these disorders. Leucocytoclastic vasculitis can be seen in granuloma faciale and erythema elevatum diutinum.

April 15, 2018
Riti Bhatia

One of those wonderful misnomers,
With clinical and histological bummers.
See early and get lured
For these neutrophils, dust and fibrin are obscure.
Wait for changes to develop
With dense eosinophils and neutrophils, fibrosis will envelop.
This solitary plaque will keep you immersed
Hideously neglecting angiocentric laryngeal whorls.

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Granuloma faciale

Granuloma faciale usually presents as a solitary well-demarcated erythematous facial plaque or nodule with prominent follicular openings and telangiectasias. Multiple lesions are seen in one-third of cases. It is a misnomer as ‘granuloma’ suggests a histological finding of granulomatous inflammation, which does not occur. Early lesions show changes like leukocytoclastic vasculitis. The distinctive changes develop with time. In addition to dense infiltrates of neutrophils, eosinophils and plasma cells, fibrosis supervenes, often oriented concentrically around small vessels. A grenz zone separates the infiltrate from overlying epidermis. Eosinophilic angiocentric fibrosis is a rare fibrosing condition that shares many histologic characteristics with GF and is regarded by some authors as a mucosal counterpart of granuloma faciale. Cases of granuloma faciale with concurrent eosinophilic angiocentric fibrosis in larynx have been reported.

March 15, 2018
Riti Bhatia

Itchy velvety plaques which are truncal,
in immunosuppressed patient will make you stumble.
Look in the epidermis for abnormal cell
Does peacock plumage ring a bell?
Trichospinulosa and Merkel carcinoma are connecting link,
This eruption will surely make you think.

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Human Polyomavirus 7 associated pruritic rash and viremia in transplant recipients

Till now only 2 polyoma viruses were known to cause skin disease in humans, these are Merkel cell polyomavirus and Trichodysplasia spinulosa polyoma virus. HPyV7 virus has been recently discovered by gene amplification studies to cause a distinctive pruritic rash in transplant recipients, appearing as velvety plaques specially on trunk. Histopathological changes are also distinctive, showing viral inclusion bodies in keratinocytes, resembling peacock plumage.

Reference: Ho J, Jedrych JJ, Feng H et al. Human Polyomavirus 7- associated pruritic rash and viremia in transplant recipients. J Infect Dis 2015:211;1560-5.

February 15, 2018
Riti Bhatia

Spot the odd one out, with reasons:
Basal cell carcinoma
Extra-mammary Paget’s diseas
Merkel cell carcinoma
Fibroepithelioma of Pinkus

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Basal cell carcinoma

Immunohistochemical staining for cytokeratin 20 (CK20) is positive in fibroepithelioma of Pinkus, Merkel cell carcinoma, trichoepithelioma and secondary forms of extra-mammary Paget’s disease but not in basal cell carcinoma. CK20 is a marker of Merkel cells, and has been used to differentiate certain forms of trichoepitheliomas (desmoplastic) and fibroepithelioma of Pinkus from BCC, which rarely expresses CK20.

Trichoepithelioma and BCC are seen as basaloid nests in dermis. A connection with overlying epidermis is seen in one-third of trichoepitheliomas. Abortive hair follicles and keratinous cysts are additional features seen in trichoepitheliomas.

Fibroepitheliomas show anastomosing cords of basaloid cells arising from epidermis with a fibrovascular stroma and with prominent Merkel cells (seen in 85% of cases). The origin of fibroepithelioma is controversial. It has been considered as a variant of basal cell carcinoma as well as trichoblastoma. The malignant potential is also uncertain.

Paget’s disease shows cells with abundant pale cytoplasm and large nuclei in epidermis, rarely extending to dermis. Extra-mammary Paget’s disease (EMPD) additionally shows abundant mucin. Cells in Paget’s disease show positive immunostaining for CEA, CA15.3, CD5 and 23, low molecular weight cytokeratins, epithelial membrane antigen and gross cystic disease fluid protein (GCDFP) variably. Cytokeratin immunophenotype has been used to distinguish primary and secondary forms of EMPD, with CK7+/CK20- seen in former and CK7-/CK20+ seen in latter.

Merkel cell carcinoma shows small cells with scant cytoplasm, arranged in trabeculae, solid nests or infiltrating sheets in dermis. CK20 is characteristically expressed with paranuclear dot-like staining.


January 15, 2018
Geeti Khullar

I come on forehead as waxy and white,
Plugged crystals behold your sight.
Yeast or bacteria may be found,
Though neutrophils also surround.
Incidentally present near a tumor,
Alcian blue will make you wonder.

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Necrotizing infundibular crystalline folliculitis

Necrotizing infundibular crystalline folliculitis (NICF) is a rare cutaneous disorder with multiple waxy folliculocentric papules appearing on seborrheic areas, particularly forehead, neck and back in adults.

The term was first used in 2001 by Kossard and colleagues. NICF is both a distinct entity and an epiphenomenon in the vicinity of epithelial skin neoplasms (secondary NICF). Histology shows follicular invagination containing filamentous birefringent crystalline deposits, enclosed by parakeratotic columns, with an underlying, partly necrotic, follicular epithelium. The filamentous material contains birefringent urate-like crystals, which are represented as Alcian blue-positive mucinous material. Perifollicular neutrophils have been observed in a few cases. On electron microscopy, the crystalline material is composed of disrupted bundles of tonofilaments embedded in an amorphous matrix.

The etiology of this entity is not yet well understood. It remains unclear whether the presence of Malassezia or Propionibacterium in the infundibulum of follicles plays a crucial role in the induction of crystalline structures or mucin. Sebum accumulation as a nutrient medium for the microorganisms has been discussed, accompanied by the accumulation of crystalline material due to the destruction of tonofilaments and the degradation of lipids, followed by a rupture of follicular epithelium and accumulation of inflammatory cells.

Clinical response to topical or systemic antibiotic and antimycotic therapies supports the theory of microbial involvement in NICF. Another possible mechanism inducing the crystalline material seems to be a chemical or physical injury. Recently NICF has also been reported to be induced by targeted anti-tumor therapies like EGFR and VEGF inhibitors.


December 15, 2017
Riti Bhatia

Spot the odd one out among the following on the basis of histopathological findings and give your reason:

Lichen striatus
Prurigo pigmentosa
Cutaneous lymphoid hyperplasia
Insect bite hypersensitivity
Necrobiosis lipoidica

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Prurigo pigmentosa
All except prurigo pigmentosa show superficial and deep perivascular mononuclear and lymphoid infiltrates. The differential diagnosis of this pattern can be remembered by the mnemonic 8Ls+ Drugs and include:

Eight ‘L’s
Light reactions,
Lymphoma (including pseudolymphomas),
Lues (syphilis),
Lichen striatus,
Lupus erythematosus,
Lipoidica (includes necrobiosis lipoidica),
Lepidoptera (insect bite hypersensitivity, parasites).
Prurigo pigmentosa shows a predominantly superficial infiltrate. In the initial phase there is a superficial perivascular and interstitial infiltrate of neutrophils. This is followed by neutrophilic spongiosis and focal epidermal microabscesses, accompanied by ballooning and degeneration of keratinocytes. This is followed by the influx of eosinophils and lymphocytes into the upper dermis. The epidermis becomes variably hyperplastic, parakeratotic, and hyperpigmented. In later stages there is prominent melanin incontinence with numerous melanophages in the dermis.

November 15, 2017
Riti Bhatia

Ashy clues and greenish hues,
Will give astute eyes, ‘the blues’
Tiny dots in eccrine glands, vessels and membranes
these ‘stars in heaven’ will jog your brains

Identify the phenomenon or pattern being referred to.

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There is a wide individual variation in the quantum and duration of exposure required to produce argyria. Following systemic intake, argyria results in an ashy to blue-black, diffuse pigmentation that affects both the skin and mucosae. The slate blue colour is due to both silver salts as well as increased melanin.

Biopsies from argyric skin appear normal at first glance apart from some increase in epidermal melanin content. On higher magnification, there are several, distinctive, uniformly sized, tiny black dots in vessel walls, around eccrine glands and in the connective tissue sheaths around hair follicles. In addition, smaller numbers may be seen lying free in the dermis.

Cutaneous silver deposits are also detectable using dark ground microscopy and electron microscopy, which may be useful in cases where no findings are seen in light microscopy. The appearance of silver deposits in dark ground microscopy is also known as ‘stars in heaven’ pattern. Electron dense deposits measuring around 100-500 nm are seen in electron microscopy.

October 15, 2017
Riti Bhatia

Single, many or only on a hair follicle,
This horny stack is not just one clonal disorder.
Look for the clues beneath,
Step cuts may be all you need.
Seen in a number of disorders,
Inflammatory, autoimmune, benign and malignant.
Gentian violet can help unveil the borders,
For biopsy site is what matters in the prototype clonal mutant

Identify the phenomenon or pattern being referred to.

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Cornoid lamellation

Cornoid lamellation is a reaction pattern which was first described by Mibelli in 1893 and is characterised by the presence of a narrow parakeratotic column. Cornoid lamella is thought to be formed by a genetically determined mutant clone of atypical epidermal keratinocytes. Porokeratosis is the prototype disorder in which this pattern is seen. Lamellar bodies, which contain lipid substances that function as a permeability barrier of the horny layer, also have acid hydrolase which causes desquamation of horny cells. Stacking of cornoid lamella horny cells may result from decreased number of lamellar bodies which brings about a defect of desquamation.

Cornoid lamellation is a change that is confined to the edge of clinical lesions and it is essential that the margin of the papule or plaque be biopsied. Some have recommended the use of gentian violet to highlight the keratotic borders, though this is not usually required.

Cornoid lamellation is characterized by a thin column of parakeratotic cells that extends through the surrounding orthokeratotic stratum corneum and to some extent above and below it. There is a marked decrease in or loss of the granular zone beneath the column of parakeratosis. Of considerable diagnostic significance is the presence of dyskeratosis or vacuolization of cells in the underlying spinous layer, just beyond the lower end of the parakeratotic column and serves to distingish the cornoid lamella from other ordinary columns of parakeratosis.The parakeratotic column is often oriented slightly obliquely with its tip slanting inwards. The papillary dermis beneath the column shows dilated capillaries with a moderately dense lymphocytic infiltrate. Multiple enlarged cornoid lamellae have been described in linear porokeratosis and in penoscrotal porokeratosis. The changes of cornoid lamellation restricted to the hair follicle have been reported.

Ultrastructurally, there is a decrease in keratohyaline granules and lamellar bodies underneath the cornoid lamella. Dyskeratotic cells beneath the cornoid lamella have vacuolated cytoplasm. Some of these vacuoles were noted to be due to vacuolated mitochondria. The cells in the parakeratotic column were flattened, more compact and had electron dense cytoplasm. The homogenous eosinophilic appearance of cornoid lamella seems to be due to stacking of ultrastructurally compact horny cells.

Porokeratosis is the prototype disorder in which cornoid lamella is observed. Wade and Ackerman observed that cornoid lamellation occurred in conditions other than porokeratosis such as seborrheic keratoses, verruca vulgaris, scar, milia, solar keratosis, squamous cell carcinoma in situ and basal cell carcinoma. It can also be seen in inflammatory disorders such as psoriasis, lichen planus like keratosis, dermatomyositis, keratosis lichenoides chronica, Grover's disease and Fox Fordyce disease.


September 15, 2017
Riti Bhatia

Look through the lens closely,
lurking in subcutis are these jagged clefts,
where the neutrophils came early,
an enzyme is what they left.
This cluster has many cells,
What you are looking for is something else.
Hallmark of a reactive dermatoses,
Are they forgotten in the glory of giant cells?

Identify the histopathological structure described.


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Miescher’s radial granuloma

Erythema nodosum is the prototype septal panniculitis without vasculitis. The septa of subcutaneous fat are thickened and infiltrated by inflammatory cells that may extend to the periseptal areas of the fat lobules. The composition of inflammatory infiltrate in the septa varies with age of the lesion. In early lesions, edema, hemorrhage, and neutrophils are seen whereas fibrosis, periseptal granulation tissue, lymphocytes, histiocytes and multinucleated giant cells are the main findings in late stage lesions. A histopathologic hallmark of erythema nodosum is the presence of Miescher’s radial granulomas, that consist of small, well-defined nodular aggregations of small histiocytes around a central stellate or banana shaped cleft. In older nodules of erythema nodosum, histiocytes coalesce to form multinucleated giant cells, many of which still retain in their cytoplasm a stellate central cleft reminiscent of those centers of Miescher’s radial granuloma. Sometimes, Miescher’s radial granulomas are conspicuous in the septa, but occasionally serial sections may be necessary to identify them. Recent immunohistochemical studies have demonstrated that the central cleft of Miescher’s radial granulomas express myeloperoxidase, which suggest that myeloid cells were present in some stage of formation.

A close differential diagnosis is subcutaneous histiocytoid Sweet's syndrome that can show Miescher's radial granulomas as well as histiocytic giant cells and clusters of mononuclear small oval cells that stain positively with myeloperoxidase. Due to these similar findings it is hypothesised that erythema nodosum and histiocytoid Sweet's syndrome may be linked.


August 15, 2017
Riti Bhatia

Sickle bodies, scars and beading,
you will look for them all.
This leonine facies has many differentials,
But the voice says it all.
When too early for onion skinning
Look at glands and vessels for a clue
PAS, colloidal iron and alcian blue
May bring your ‘pale’ intuition true!
Discovered by two Viennese,
What is the name of this disease?

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Lipoid proteinosis

Lipoid proteinosis, also known as hyalinosis cutis et mucosae, is a rare autosomally recessive disorder characterized by widespread deposition of hyaline material in the skin, mucosa, and various internal organs. It was first described in 1929 by two Viennese, E. Urbach and C. Wiethe, a dermatologist and an otorhinolaryngologist, as lipoidosis cutis et mucosae based on the deposition of lipoid material with protein in the skin and mucous membranes. It was renamed as lipoid proteinosis to avoid confusion with other lipidoses. The first clinical presentation of lipoid proteinosis is usually hoarseness of voice due to infiltration of the laryngeal mucosa, which usually appears in early childhood. Cutaneous lesions develop afterwards or simultaneously. Skin lesions occur in two phases. Vesiculo-bullous lesions, pustules, and hemorrhagic crusting of the skin and mucosae characterize the first stage (inflammatory). These lesions heal with “ice pick” acneiform scarring, mainly over the face and distal extremities. In the second phase, yellowish waxy papules, nodules, and plaques occur over the face. Hyperkeratotic verrucous plaques may also be seen around the elbows or knees. Rarely, generalized infiltration may develop. Beaded papules over the palpebral margin of the eyelid, known as ‘moniliform blepharosis’ are characteristic of lipoid proteinosis. The mucosae of the pharynx, vocal cords, tongue and lips show an infiltration similar to that seen in the skin. The tongue is firm and enlarged with restricted mobility. Lesions may also be present in the soft palate, uvula, epiglottis, aryepiglottic fold, and, rarely, in the mucosa of the labia and vagina. Other uncommon manifestations include dental anomalies like hypoplasia or aplasia of teeth, patchy alopecia, diffuse hair loss, and recurrent parotitis. Widespread visceral involvement has been described, although few cases develop significant clinical symptoms. Neurologic manifestations are common and include psychomotor and grand mal seizures, memory loss, and schizophrenia. The pathognomonic finding in the CT scan of the head is bilateral, intracranial, sickle shaped calcification within the temporal lobe of the brain.
Histological examination of the lesional skin with hematoxylin-eosin stain shows progressive deposition of pale, eosinophilic, hyaline material in the superficial dermis, but this is initially localized around small blood vessels and at the periphery of eccrine sweat glands. In advanced lesions, the deposits around blood vessels may have an ‘onion-skin’ appearance. The epidermis may show hyperkeratosis and some acanthosis in the verrucous lesions. The hyaline deposits are PAS positive and diastase resistant. They stain positively with colloidal iron and Alcian blue at pH 2.5 and also with Sudan black and oil red O on frozen sections. Ultrastructurally, fine collagen fibrils, embedded in an amorphous matrix, are seen. There is prominent reduplication of the basal lamina at the dermoepidermal junction and concentrically around vessels.
Porphyria also shows similar amorphous deposits in skin biopsy. However, the deposits in the latter condition are more limited in distribution, being perivascular only. Sweat glands are not involved in porphyria.


July 15, 2017
Riti Bhatia

Dilated cystic spaces in sclerotic stroma,
Leave you mesmerized with a ‘comma’
Provocative shapes of epithelial islands
Involucrin, CEA, BerEP4 and CK20 are all their stains.
Perineural invasion, horn cysts or retraction cleft
Are clues to some of them in this ‘patterned set’

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Paisley-tie pattern

Paisley tie tumors are a histological group of tumors consisting of syringomas as prototype along with desmoplastic trichoepithelioma, morpheic basal cell carcinoma and microcystic adnexal carcinoma.
Syringomas are dermal tumors composed of multiple small ducts lined by two layers of cuboidal epithelium.
Desmoplastic trichoepitheliomas are composed of cords and small nests of basaloid cells with scanty cytoplasm. Tumor strands may be attached to the epidermis. There are usually many keratinous cysts, with a peripheral basaloid layer and several layers of stratified squamous epithelium with central loosely laminated horn. Comma shaped epithelial projections extend from the peripheral layer of some of the keratinous cysts. The tumor cells do not contain carcinoembryonic antigen, unlike the cells in a syringoma, which are usually positive. In contrast, involucrin is expressed in desmoplastic trichoepitheliomas but not in syringomas. Merkel cells (CK20) are present in desmoplastic trichoepitheliomas but are uncommon in basal cell carcinoma.
Microcystic adnexal carcinoma usually involves the subcutis as well as the dermis, and it may extend into the underlying muscle. The superficial part is composed of numerous keratinous cysts and small islands and strands of basaloid and squamous epithelium showing variable ductal differentiation. Perineural invasion is frequently present. The aggressive growth and perineural spread allow a distinction to be made from syringoma and desmoplastic trichoepithelioma. In some of the reported cases of microcystic adnexal carcinoma, the luminal cells were CEA positive.
Sclerosing or morpheic type of basal cell carcinoma shows narrow elongated strands and small islands of tumor cells embedded in a dense fibrous stroma. Ber-EP4 is positive focally in most trichoepitheliomas, contrasting with the usual diffuse staining in basal cell carcinoma.

June 15, 2017
Riti Bhatia

Large cells with ample pale cytoplasm,
small white patches on skin,
Will you think of a neoplasm,
and stain it with PAS, EMA and cytokeratin?
When in doubt,
look for ‘the line’
Biopsy may give you second thoughts
what is your take, malignant or benign?

Click to show/hide the answer

Clear cell papulosis

This is an extremely rare entity affecting children in the age group of 1-4 years. It is considered to be a benign counterpart of extra-mammary Paget’s disease. Affected patients present with hypopigmented macules and papules on the anterior chest and abdomen, usually along the milk line. These resolve spontaneously with age.

Biopsy from involved skin shows acanthosis and ‘clear cells’ which are large keratinocytes mainly found in the basal layer of epidermis and in lesser numbers in the upper layers. These cells contain abundant mucin. Focal clustering and nuclear grooving of these cells has been observed by some authors. The cells closely resemble Toker cells in the nipple as well as Paget cells but can be differentiated by the presence of intra-cytoplasmic mucin in clear cell papulosis, which is not seen in Toker cells. The immunohistochemical profile of these cells suggests an eccrine origin as they stain with carcinoembryonic antigen, cytokeratin CK-7, epithelial membrane antigen and IKH-4 antibody and do not stain or stain weakly with gross cystic disease fluid protein antigen.

Paget cells, on the other hand, stain strongly with gross cystic disease fluid protein antigen, suggesting an apocrine origin. The clinical features, age of onset and immunohistochemistry are helpful in differentiating clear cell papulosis from other conditions with clear cells in the epidermis including extra-mammary Paget’s disease, pagetoid squamous cell carcinoma, sebaceous carcinoma and pagetoid melanoma.

The hypopigmentation may be due to a defect in melanogenesis as suggested by a report of reduced melanin pigment in the areas of epidermis occupied by clear cells.

In clear cell/pale cell acanthoma, solitary or multiple brownish nodules are present on the legs of middle aged individuals that show large pale staining keratinocytes in acanthotic epidermis.

May 15, 2017
Riti Bhatia

Light or dark on skin, pale in biopsy always.
Look for me superficially, horizontal are my ways.
I may be alone or in a syndrome, upper body is where I am seen.
When stuck with peripheral palisading, you will find the answer with orcein.

What is your diagnosis?

Click to show/hide the answer

Tumor of follicular infundibulum

This is an uncommon benign adnexal tumor that usually presents as a solitary keratotic papule in the head and neck area in elderly. Infrequently, it may present as multiple lesions or in association with syndromes like the Schöpf–Schultz–Passarge syndrome and Cowden’s syndrome.
Histopathologically, the tumor is comprised of a superficial horizontal plate-like proliferation of eosinophilic, pale-staining keratinocytes with a peripheral palisading of basaloid cells. Mutifocal connections between tumor strands, epidermal surface and existing follicular structures can be seen, creating a reticulated pattern. Some cases also contained small horn microcysts with keratohyaline granules and small tubular structures with an eosinophilic wavy lining resembling sebaceous ducts. Occasionally, the infundibulocystic structures appeared to be connected to entrapped follicles in the lesions. It shows a characteristic staining pattern, with abundant glycogen highlighted by periodic acidSchiff (PAS) staining, and prominent elastic fiber ‘sheathing’ around the tumor collections. The brush-like elastic network helps distinguish tumor of follicular infundibulum from basal cell carcinoma and seborrheic keratoses, which lack this feature.

April 15, 2017
Riti Bhatia

What is the connecting link between progressive symmetric erythrokeratoderma, papillomatosis cutis carcinoides and acrogeria?

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The term Gottron links all of these.

Progressive symmetric erythrokeratoderma,also known as Gottron's syndrome, is characterized by well-defined, erythematous, hyperkeratotic plaques distributed mainly on the knees, elbows, buttocks, head and dorsal surfaces of the hands and feet. Onset is during early childhood. The histopathological findings are not distinctive. There is hyperkeratosis, irregular acanthosis, very mild papillomatosis in some biopsies, and a mild superficial perivascular infiltrate of lymphocytes. Dyskeratotic, grainlike cells may be seen in the lower stratum corneum. There may be parakeratosis and some vacuolation in the lower horny cells and in the granular layer.
Papillomatosis cutis carcinoides, also known as Gottron tumor, consists of a group of verrucous carcinomas that are locally invasive and destructive but rarely metastasize.
Acrogeria is also called Gottron’s syndrome. It is an exceedingly rare disease, with onset in early childhood. There is atrophy, dryness, and wrinkling of the skin which is most severe on the face and extremities. Associations include bony abnormalities and disorders of dermal elastic tissue in the form of elastosis perforans serpiginosa and perforating elastomas. There is atrophy of the dermis with degenerative changes in the collagen. Fibers may be swollen and present a ‘boiled’ appearance. The subcutaneous fat is often replaced by connective tissue which is indistinguishable from the dermal collagen. Elastic fibers are disrupted and irregular, with some clumping.

March 15, 2017
Geeti Khullar

Which of the following is the odd one out and why?

1. Post kala-azar dermal leishmaniasis
2. Erythema elevatum diutinum

3. Mycosis fungoides

4. Dermatofibroma


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Mycosis fungoides

Mycosis fungoides does not show the presence of a grenz zone. A grenz zone can be seen in 48% cases of nodular PKDL, 75% cases of erythema elevatum diutinum and 70% cases of dermatofibroma. It is important to note that the presence of grenz zone, earlier considered to differentiate granuloma faciale from erythema elevatum diutinum is no longer used to differentiate between these two entities.


February 15, 2017
Meenakshi Batrani

Identify the common morphological (gross or microscopic) term for the following entities:
1. Elastofibroma
2. Trichorrhexis nodosa
3. Actinomycetoma
4. Lipoid proteinosis
5. Atypical mycobacteria

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Elastofibroma shows beaded coarse elastic fibres. Trichorhrexis nodosa shows beaded hair shaft. The granule of actinomycetoma is composed of beaded gram positive filaments. Beaded eyleid papules are a characteristic clinical finding in lipoid proteinosis, Atypical mycobacteria especially Mycobacteria kansasii shows a coarsely beaded appearance on acid fast staining.

January 15, 2017
Meenakshi Batrani

Identify the common morophological term for the following entities:
1. Borderline leprosy
2. Erythema elevatum diutinum
3. Lipoid proteinosis
4. Perineuroma
5. Myopericytoma

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Onion skin pattern

Borderline leprosy: perineural onion skin fibrosis.
Erythema elevatum diutinum: perivascular onion skin fibrosis in late lesions.
Lipoid proteinosis: perivascular onion skin hyaline deposits.
Perineuroma: sclerosing perineuroma shows a whorled onion skin growth pattern.
Myopericytoma: myoid cells/pericytes arranged concentrically in onion skin pattern around blood vessels.

December 15, 2016
Riti Bhatia

From nevi to lentigenes to melanoma,
I resemble all those big names.
Young people are my favourite,
I go away without giving any pains.
The upper you go,
Better will be the clues.
Stain me with Perls or Benzidine
Which stain will you choose?

Identify the condition and stain used.

Click to show/hide the answer

Calcaneal petechiae/talon noir, Benzidine stain

This condition, also known as black heel, presents with dark spots of recent origin usually on the soles of the feet. Lesions are usually bilateral and there is a history of jogging or prolonged walking, hence it affects young people or athletes more often. Eruptive nevi, lentigenes, acral nevi/melanoma may be considered as the differential diagnoses, especially when it is not suspected clinically.
Skin biopsy shows findings confined to the stratum corneum which shows intracorneal hemorrhage. Depending on how old the hemorrhage is, there can be RBCs, or an orange-yellow stained crust. This material stains negatively with Perls stain for hemosiderin but often stains positive with benzidine for hemoglobin.
Dermoscopy has also been used for diagnosis. It shows homogenous reddish pigmented globules of hemorrhage. Sometimes this may be arranged along the crests giving a parallel appearance, mimicking acral melanoma.
It has been suggested that paring alone may reveal blood in the stratum corneum obviating the need for a biopsy. Once the pigmentation is confirmed to be due to blood, the diagnosis is established and other conditions can be safely excluded. Lesions resolve spontaneously in a few days, but may recur.

November 15, 2016
Riti Bhatia

What is the common term that links these conditions: hidroacanthoma simplex, pachyonychia congenita, blue nevus and a rare form of ectodermal dysplasia with keratin mutation?

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Borst-Jadassohn phenomenon is characterised by well-demarcated nests of uniform, basaloid cells confined within the epidermis, most often associated with benign lesions such as seborrheic keratosis (especially if irritated by infection or trauma) or entirely intraepidermal sweat gland tumors (hidroacanthoma simplex of Smith and Coburn). Less commonly, it may be seen in clonal actinic keratosis, Bowen's disease, melanoma in situ, Paget's disease and epidermotropic metastatic carcinomas.

Jadassohn-Lewandowski Syndrome is the other name for pachyonychia congenital, an autosomal dominant disorder with mutation in the highly conserved 1A domain of K6, K16 and K17 (chromosome 17). The characteristic features include:abnormally thick curved nails (onychogryposis)/ wedged door abnormality, palmoplantar keratoderma, palmoplantar hyperhidrosis and oral leukoplakia.

Common blue nevus is also known as Jadassohn-Tie`che blue nevus as it was first described by Tie`che, a student of Jadassohn in 1906. Common blue nevus is a grey-black macule or a papule commonly found on dorsae of extremities and head and neck regions. Other variants of blue nevus are cellular, combined, sclerosing and epithelioid blue nevi. Histopathologically, there are elongated dendritic melanocytes in the interstices of collagen in upper and mid dermis in common blue nevus. Cellular blue nevus additionally shows some islands of epithelioid cells and plump spindle cells, with abundant cytoplasm. Dermal fibrosis is a prominent finding along with dendritic melanocytes in the dermis in sclerosing blue nevus. Combined blue nevus shows a junctional melanocytic nevus along with the features of common blue nevus.

Naegeli-Franceschetti-Jadassohn Syndrome (MIM 161000) is a rare autosomal dominant form of ectodermal dysplasia that results from mutations in the KRT14 gene located on chromosome 17q11.2-q21. It is characterised by complete absence of the patterned ridges on the skin of the hands and feet, called dermatoglyphics that are the basis for each person's unique fingerprints, reticulate pattern of skin hyperpigmentation, palmoplantar keratoderma, abnormal sweating and enamel defects. It closely resembles dermatopathia pigmentosa reticularis and is distinguished by lifelong persistence of the skin hyperpigmentation, partial alopecia, and absence of dental anomalies in dermatopathia reticularis pigmentosa.

October 15, 2016
Vishal Gupta

Based on histopathologic features, which one among the following is the odd one out and why?

1. Erythema toxicum neonatorum
2. Transient neonatal pustular melanosis
3. Acropustulosis of infancy
4. Miliaria pustulosa
5. Neonatal acne

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Erythema toxicum neonatorum
It is characterised by eosinophilic infiltrates in biopsy from a pustule while all the rest are predominantly neutrophilic.

All these entities are differential diagnoses for vesiculopustular lesions in a neonate. Erythema toxicum neonatorum is a common, self-limited entity which appears within the first few days of life as erythematous macules, papules, and pustules, mostly located on the trunk. The lesions resolve within a few days leaving no sequelae. There are subcorneal or intraepidermal pustules, filled with eosinophils and related to the orifices of the pilosebaceous follicles. An inflammatory infiltrate composed predominantly of eosinophils is present in the upper dermis in the vicinity of the follicles, and there is some exocytosis of these cells into the epithelium of the involved follicles.

Transient neonatal pustular melanosis is an uncommon condition that presents at birth with pigmented macules, often with a distinct collarette of scale, and vesiculopustules which are clustered beneath the chin, on the forehead, the neck and the back, and sometimes on the extremities. The vesiculopustules usually resolve after several days, often transforming into pigmented macules. The pigmented lesions persist for several weeks or more and then slowly fade. The vesiculopustules are intracorneal or subcorneal collections of neutrophils, admixed with fibrin and a few eosinophils. There may be a mild infiltrate of inflammatory cells around vessels in the upper dermis.

Acropustulosis of infancy is an uncommon pustular dermatosis characterized by recurrent crops of intensely pruritic vesiculopustules on the distal parts of the extremities of infants. The lesions measure 1–2 mm in diameter. Its onset is at birth or in the first few months of life, and resolution occurs at 2–3 years of age. There is an intraepidermal pustule containing neutrophils and sometimes varying numbers of eosinophils. This progresses to form a subcorneal pustule.

Miliaria pustulosa is characterized by neutrophils beneath the stratum corneum and/or in the epidermal sweat duct.

Neonatal acne or benign cephalic pustulosis is characterised by inflamed papules and pustules on the face of neonates. Skin biopsy from these shows follicular pustules with neutrophils.

September 15, 2016
Riti Bhatia

What is the connecting link between multiple basal cell carcinomas, Ehlers-Danlos disease and focal dermal hypoplasia?

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The term Gorlin links all of these.

The nevoid basal cell carcinoma syndrome, also known as Gorlin’s syndrome, is a multisystem disorder characterized by multiple basal cell carcinomas with an early age of onset, odontogenic keratocysts, pits on the palms and/or soles, cutaneous cysts, skeletal and neurological anomalies, and ectopic calcifications. Often there is a characteristic facies, with hypertelorism and an enlarged skull. Less common manifestations include lipomas and fibromas of various organs, fetal rhabdomyoma, unilateral renal agenesis, adenoid cystic carcinoma of minor salivary gland, ovarian cysts, and medulloblastomas. Its prevalence is estimated to be 1 in 57 000 to 1 in 164 000. The inheritance is autosomal dominant with mutation in the patched homologue 1 (PTCH1) gene on chromosome 3.

Goltz-Gorlin syndrome is the other name for focal dermal hypoplasia, in which the skin biopsy shows reduced thickness of the dermis, with some thin, loosely arranged collagen fibers in the papillary dermis. Clusters of adipocytes may be anywhere in the dermis or in a perivascular location. The extreme degree of attenuation of the collagen seen in focal dermal hypoplasia is not present in nevus lipomatosus, in which mature fat also replaces part of the dermis; furthermore, the clinical presentations of the two conditions are quite distinct.

Gorlin sign is the ability to touch the tip of the nose with the tongue. It is seen in 50% of patients of Ehlers-Danlos syndrome.

August 15, 2016
Riti Bhatia

Which of the following is the odd one out and why?

CHILD syndrome
Verruciform xanthoma
Hidradenitis suppurativa
Fox-Fordyce disease

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Hidradenitis suppurativa
All the other diseases show foamy histiocytes as a distinctive finding while hidradenitis suppurative does not.

Verruciform xanthoma. On the basis histological appearance the epithelial changes in verruciform xanthoma have been been divided into three groups-verrucous, papillary, and flat-and these epithelial changes reflect the clinical picture of the lesion. The diagnostic histological finding, however, whether intra- or extraoral in location, is the presence of foam cells that fill the dermal papillae and submucosal space. These foam cells have been shown to have monocyte/macrophage lineage.

CHILD syndrome. Histopathological examination reveals psoriasiform epidermal hyperplasia and, sometimes, verruciform xanthoma like features, i.e., foamy histiocytes in the upper papillary dermis.

Fox Fordyce disease. There is an associated mild to moderate inflammatory cell infiltrate which may contain some neutrophils as well as chronic inflammatory cells. Perifollicular foam cells have been found to be a relatively consistent and distinctive feature.

Hidradenitis suppurativa. In established lesions, there is a heavy, mixed inflammatory cell infiltrate in the lower half of the dermis, usually with extension into the subcutis. Chronic abscesses are present in active cases and these may connect with sinus tracts leading to the skin surface. The sinuses are usually lined by stratified squamous epithelium in their outer part. Granulation tissue containing inflammatory cells and occasional foreign body giant cells is present in up to 25% of cases. Inflammation of the apocrine glands may be present in the axillary region in about 20% of cases. Perieccrine inflammation is seen in approximately one-third of cases, from all sites. In early lesions, there is folliculitis and perifolliculitis involving the lower part of the follicle. The infundibulum is usually dilated and contains keratinous material and inflammatory debris. These findings support the notion that acne inversa is primarily a follicular disease, but apocrine glands can be primarily involved in a minority of axillary lesions.

July 15, 2016
Rajalakshmi T

Which is the odd one out and why?

1. Cylindroma
2. Spiradenoma
3. Fibrofolliculoma
4. Trichoepithelioma

Click to show/hide the answer


The other three tumors i.e. cylidroma, spiradenoma and trichoepithelioma are components of Brooke-Spiegler syndrome, an autosomal dominant syndrome with mutations in the CYLD gene on chromosome 19q. Salivary gland tumors are also seen. Multiple Fibrofolliculomas and Trichodiscomas, on the other hand, are seen in Birt-Hogg-Dube syndrome, characterised by mutations in the BHD gene on 17p. These patients may also have renal tumors and lung cysts.

June 15, 2016
Khalid Al Aboud

Which is the wrong number among these and why?
CD 117, CD 2, CD 14, CD 25

Click to show/hide the answer

CD 14. The rest are markers for mast cells.

Immunostains are of great help in diagnosing mast cell (MC) disorders.

Tryptase: positive in all mast cells, normal or neoplastic, granular, intracytoplasmic staining.

CD117: membranous staining, together with tryptase helps in differentiating mast cells from basophils.

CD2: weak positive in neoplastic mast cells, even stronger in surrounding reactive lymphocytes

CD25: positive in neoplastic mast cells.

Presence of mast cells which co-express CD117 and CD2 and/or CD25 is one of the minor criteria for the diagnosis of systemic mastocytosis.

CD 14 is a monocytic/histiocytic marker. Mast cells do not stain with it.

May 15, 2016
Khalid Al Aboud

I demonstrate dusky dappled disfigurements
and dark dot depressions,
disclosing digitate downgrowths delving dermally.
Who am I?

Click to show/hide the answer

Dowling Degos Disease

The statement given in the question is a memorable description of Dowling–Degos disease by Wilson-Jones and Grice (see reference below).
Dowling–Degos disease is also known as reticulate pigmented anomaly of the flexures. It is an autosomal dominant disorder that affects the skin of the back, neck and axillae in the form of pigmented, reticulate macules/papules .There might be also pitted perioral or facial scars. Mutation in keratin 5 (KRT5) was found in this disorder. Galli–Galli disease is the acantholytic variant of this disease.
Histopathology shows elongated, pigmented rete ridges (filiform, “antler-like” downgrowths); thinning of suprapapillary epithelium; perivascular infiltrate and dermal melanosis.
Differential diagnoses include reticulate acropigmentation of Kitamura and adenoid form of seborrheic keratosis, although the downgrowths are more digitate than in seborrheic keratosis and there is no papillomatosis.

Wilson-Jones E, Grice K. Reticulate pigmented anomaly of flexures (Dowling–Degos): a new genodermatosis? Br J Dermatol 1974; 91 (Suppl. 36): 6.

April 15, 2016
Contributed by Rajalakshmi T

I favour the head and neck,
I show continuity with infundibula,
I am populated by dark and pale cells,
I show ducts, but only within the pale areas,
Necrosis is my good friend.

Who am I?

Click to show/hide the answer

Apocrine poroma

Poromas are skin adnexal neoplasms with prominent ductal differentiation, comprising of dark poroid and pale cuticular cells. The ducts are always seen within the cuticular cells. There are three architectural variants: hidroacanthoma simplex (confined to the epidermis and sharply demarcated), classic poroma (aggregates that protrude into the upper dermis) and dermal duct tumor (tumor cells situated deep within the reticular dermis). Poromas can be eccrine or apocrine. Eccrine poromas classically occur on the extremities. In contrast, apocrine poromas are common on the head and neck and show continuity with infundibular structures. It is important to note that necrosis and mitoses are common in poromas and do not indicate malignancy.

March 15, 2016
Contributed by Meenakshi Batrani

I have a red face with a goggle!
Drugs make me sparkle!!
Burning in the flame, I always take the blame!!
Insects give me fame!
Just guess my name!!

Click to show/hide the answer


Eosinophils are characterised by bright orange red granules and a bilobed nucleus. Eosinophilic dermal infiltrate is a feature of drug reactions and insect bites. In Well's syndrome, eosinophilic infiltrate forming flame figures is seen. Flame figures comprise of granules from eosinophils coating degenerate, blue collagen bundles in loci. Among bullous diseases, eosinophils are frequently encountered in bullous pemphigoid, pemphigus vulgaris and foliaceus.

February 15, 2016
Contributed by Meenakshi Batrani

I am the freshener of the mouth, brightening many a cloud!
Excess of me you take, will make you like a slate!!

Who am I and what condition do I cause?

Click to show/hide the answer

Silver, causing argyria

Silver is used as a coating in many mouth fresheners including cardamom and betel nut, Jintan in Japan. Excess intake of silver imparts a slate-grey pigmentation.

Argyria is a rare cause of cutaneous discolouration caused by silver deposition. Argyria can be localized or generalized, depending upon the mode and amount of silver absorbed. In general, the macular pigmentation in argyria is slate-grey. It is more pronounced on sun exposed areas including face, neck, arms and dorsum of the hands. Mucosal/conjunctival involvement and azure lunulae (of nails) are characteristic attributes of argyria. Diagnostic histopathologic features are deposition of uniform fine brown black granules in the basal lamina of the secretory portion of eccrine glands, blood vessel walls and elastic fibres of the papillary dermis. To a lesser extent, deposits are also seen in the connective tissue sheath surrounding pilosebaceous units, perineural tissue and arrector pili muscles. Dark field microscopy under which the granules are brightly retractile is particularly useful in suspected cases of argyria where the deposits are not evident under light microscopy.

January 15, 2016
Contributed by Geeti Khullar, Saurabh Singh

Although my founder literally adorns the ocular cilium; in life horny and not so pretty I am.
I may appear to love solitude, multitude, genetics or may even be reactive; I tend to embellish the senile more than the active.
Closer you look and the deeper you tread; I get ducts embedded in strings-strands, and vessels and mast cells in the bed.
Behold my often benign innocent ways, I may dawdle to cancery lanes.
Don’t put thy intellect to shame, what shall be my lengthy name?

Click to show/hide the answer

Eccrine syringofibroadenoma

Eccrine syringofibroadenoma (ESFA) is an uncommon condition described by Mascaro in 1963. The age of onset ranges from 16 to 80 years, however, mostly it affects patients in their seventh and eighth decades. It may show a variable presentation, including solitary lesions, multiple papules and nodules arranged in a symmetrical or linear nevoid pattern, associated with hidrotic ectodermal dysplasia or as a reactive phenomenon occurring in inflammatory conditions like bullous pemphigoid, psoriasis, lichen planus, leprosy, etc.

Clinically, it presents as hyperkeratotic plaques usually on the extremities. Histopathology demonstrates thin anastomosing epithelial cords and strands forming a lattice and connected to the undersurface of the epidermis. The cells are smaller and more basophilic than the epidermal keratinocytes. Ducts are present within the tumor. Between the strands there is a rich fibrovascular stroma comprising of mast cells, lymphocytes and plasma cells. Carcinomatous transformation has been reported in long standing lesions.

December 15, 2015
Contributed by Rajalakshmi T

What is the descriptive term (microscopic, gross or imaging) common to the following conditions?

1. Melanoma
2. Syphilis
3. Fibromatosis
4. Scurvy


Click to show/hide the answer


The common descriptive terminology for all these conditions is "corkscrew".
The vascular pattern of melanoma on dermoscopy is termed as corkscrew. In syphilis, the spirochaetes have a corkscrew appearance on Warthin-Starry or other silver impregnation techniques. Fibromatoses comprises a group of proliferations spanning various age groups that may be locally aggressive and are characterised histologically by corkscrew-like myofibroblasts. In scurvy, one sees corkscrew hair and pinpoint haemorrhages around hair follicles. This feature is usually appreciated in adults.



November 15, 2015

Contributed by Rohini Mathias

Which is the eponym common to the three descriptions listed below?

1. Used to characterize and discriminate between various connective and soft tissue elements of a lesion

2. Clinical mimic of angiosarcoma

3. Used to highlight melanocytic lesions


Click to show/hide the answer

The eponym is 'Masson'.

Claude L. Pierre Masson (12th November 1880 – 11th May 1959) was a French born histopathologist from Quebec. Despite having a keen interest in clinical medicine, he studied basic sciences and became one of the most famous pathologists of his time. His name was entered in the 'Canadian Medical Hall of Fame' in 1997.

The Masson's trichrome is a three color staining protocol used to distinguish various connective and soft tissue elements. Muscle fibres stain red and collagen green.

Masson's pseudoangiosarcoma ( hemangio-endotheliome vegetant intravasculaire or Masson's hemangioma or papillary endothelial hyperplasia) was described by Masson in 1923 as a neoplastic process mimicking angiosarcoma in infected hemorrhoidal veins. It is now known to be an unusual organization of a thrombus within a vein or within vessels of various vascular anomalies such as cavernous hemangiomas, lymphangiomas and pyogenic granulomas. Clinically, it presents as single or multiple, small, occasionally painful, firm blue nodules. Microscopically, it is a widely dilated vascular channel in the dermis or subcutis containing an organizing thrombus and blunted papillary projections with a hyalinized collagenous core. The papillae are lined by a single layer of plump endothelial cells that lack anaplasia or pleomorphism unlike angiosarcomas.

The Fontana- Masson stain is a silver stain that stains argentaffin granules and melanin black.



October 15, 2015
Contributed by Rajalakshmi T

All the following statements are true about a particular disease except one:

a. They occur more frequently in blacks
b. They stain positive for Factor XIIIa.
c. They contain dendritic melanocytes
d. They stain variably with CD34.

Which is the condition described above and which statement is incorrect?


Click to show/hide the answer

Pigmented DFSP/Bednar tumor
Statement b is incorrect.

Bednar tumor is a variant of DFSP, very common in Africans or African-Americans. It is characterised by dermal-based spindle cells arrayed in a storiform and fascicular pattern. Dendritic melanocytes are interspersed. It is locally aggressive. Immunohistochemically, the neoplastic cells express CD34, which may be lost during transformation to higher grade malignancy. The melanocytes express S100. Factor XIIIa, which marks dermatofibromas is negative in this tumor.


September 15, 2015

Contributed by Rohini Mathias

Pick out the histologic metaphor that does not fit, with a justification for your choice:

1. Lump of coal on a pillow
2. Toy soldier appearance
3. Eyeliner sign
4. Bare under belly sign


Click to show/hide the answer

The 'pathological misfit' is the 'eyeliner' sign.

This sign seen in Bowen's disease refers to the intact normal basal layer despite the full thickness atypia of the rest of the epidermis.

The other mentioned signs are features of mycosis fungoides (MF). In early MF, atypical lymphocytes line up along the dermoepidermal junction demonstrating epidermotropism (row of toy soldiers or string of pearls appearance). Large atypical lymphocytes lying singly within the epidermis having irregular hyperchromatic nuclear contours with clear perinuclear haloes are likened to a 'lump of coal on a pillow'. A relatively unreliable sign encountered in some cases of MF is the 'bare underbelly sign' which describes the presence of lymphocytes on the epidermal side of the superficial vascular plexus, an indication of their epidermotropic nature.


August 15, 2015

Contributed by Rohini Mathias

Fever and lipodystrophy
growth retardation and hepatomegaly,
Annular lesions with typical facies,
are the clinical features one sees....
there's a mixed dermal and subcutaneous MPO positive infiltrate,
know this bright new syndrome and you're up to date!

What is the disease described above?


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Chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature syndrome (CANDLE syndrome)

CANDLE syndrome is a rare autosomal recessive autoinflammatory disease which occurs due to a mutation in the PSMB8 gene leading to a dysregulation of the interferon signalling pathway. It presents in early infancy with recurrent fever and physical growth retardation. Patients have a typical facies: thick lips, violaceous swollen eyelids and facial lipodystrophy. Skin lesions are erythematous to violaceous annular plaques that last days to weeks and fade with a residual purpuric stain. Other features include hepatomegaly, peripheral lipodystrophy, arthralgia, nodular episcleritis, conjunctivitis, auricular and nasal chondritis, splenomegaly, anemia and aseptic meningitis.

Skin lesions show an extensive mixed dermal and subcutaneous inflammatory infiltrate composed predominantly of atypical myeloid cells and mature neutrophils in addition to eosinophils and mononuclear cells.



July 15, 2015

Contributed by Rohini Mathias

The syndrome characterised by multiple cutaneous neoplasms having a fenestrate pattern of mantle-like cells with clusters of sebocytes at times is also associated with all of the the following, except:

1. Renal oncocytoma
2. Renal medullary carcinoma
3. Chromophobe renal cell carcinoma
4. Papillary renal cell carcinoma


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Renal medullary carcinoma

Multiple cutaneous neoplasms characterised by fenestrate pattern of mantle-like cells surrounded by ribbon like collagen bundles (fibrofolliculoma) with clusters of sebocytes at times (trichodiscoma, a variant) are seen in Birt-Hogg-Dube syndrome. It is a rare disease, associated with lung cysts and increased predisposition to develop renal tumors. The common renal neoplasms seen are chromophobe renal cell carcinoma, oncocytoma and rarely clear cell carcinoma, papillary carcinoma. There may also be tumors in other organs like thyroid and the gastrointestinal tract. The disease occurs as a consequence of mutations in the folliculin gene.

Renal medullary carcinoma is a rare, aggressive neoplasm classically seen in patients with sickle cell disease.


June 15, 2015

Contributed by Rohini Mathias

Pick the odd one out from these metaphorical histologic terms and give the reason for your choice.

1. Shark's tooth
2. Paisley tie
3. Rolls and scrolls
4. Onion skin


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Paisley tie

'Paisley' pattern, a droplet shaped vegetable motif of Persian origin is a popular design on various jewelry and textiles including ties. A 'paisley tie' or 'tadpole' appearance in dermatopathology is encountered in syringoma, microcystic adnexal carcinoma, morpheaform basal cell carcinoma and desmoplastic trichoepithelioma to describe the configuration of tumor cell nests.
The other options are descriptive terms for a pattern of keratinization seen in adnexal cysts of pilo-sebaceous origin.
'Sharks tooth' cuticle is the wavy eosinophilic crenulated appearance of the cyst wall in steatocystoma multiplex. 'Rolls and scrolls' is seen in a proliferating pilar cyst, as the epithelium proliferates, the wall buckles inward rolling on itself producing a trabecular or scroll like appearance. 'Onion skin' is the stratified lamellated appearance of corneocytes in the lumen of epidermoid and vellus cysts.



May 15, 2015

Contributed by Rohini Mathias

Your patient is a febrile Latino with mulberries in his mouth,
Though the histology looks like cancer, there’s a granuloma without a doubt!
So sail across the oceans and grab hold of the mariners wheel,
Then to us your diagnosis you can confidently reveal….

Which disease is being described here?


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Paracoccidiodomycosis/ South American Blastomycosis/ Lutz-Splendore-de-Almeida disease

Paracoccidiodomycosis is a systemic mycosis, endemic to South and Central America, caused by the dimorphic fungus Paracocciodes brasiliensis. The fungus is a saprophyte and the portal of entry is usually the respiratory tract. Direct man to man transmission does not occur.
The less common acute or subacute forms manifest as fever with constitutional symptoms, skin lesions, lymphadenopathy and hepatosplenomegaly. The more common chronic or adult form presents with pulmonary features (cough, dyspnoea, fibrosis, bullae and emphysematous changes), oropharyngeal and laryngeal mucosal involvement (typical presentation being erythematous ulcers with a granulomatous base intermixed with hemorrhagic spots, the so called moriform stomatitis of Aguiar-Pupo), polymorphic cutaneous lesions (crusted papules, ulcers, verrucous plaques and nodules) and lymphadenopathy.
The histopathological findings include pseudoepitheliomatous hyperplasia with intraepithelial abscesses and epithelioid granulomas with foci of suppuration.
The hallmark feature is the presence of round, large and small budding yeast cells which often demonstrate multi-lateral budding giving it the typical mariners or pilots 'steering wheel' appearance. These may be found within macrophages and foreign body giant cells or lying free in tissue and are more easily demonstrable using silver stains.


April 15, 2015

Contributed by Rohini Mathias

Usually spotted in the Native American and Inuit race,
These lesions are found on a mucosa in the face.
A virus has been incriminated in its etiology,
An axe from the bronze age is what you see on microscopy!

Which condition is this?


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Focal epithelial hyperplasia or Heck disease

Focal epithelial hyperplasia or Heck disease is an uncommon viral proliferation (HPV 13 and 32) of the oral mucosa encountered mainly in Eskimos (Inuits) and Native Americans.

It is usually seen in children or young adults and clinically manifests as multiple pink or whitish papules or nodules in the oral mucosa. The diagnostic histologic appearance is the 'bronze age battle axe' appearance which is an abrupt and considerable focal acanthosis with clubbing and occasional anastamosis of the rete ridges. Another feature is the presence of 'mitosoid' cells or cells resembling those in various phases of mitosis, though they actually lack mitotic ability. These are degenerating epithelial cells with irregular hyperchromatic nuclei found in clusters in the upper stratum spinosum.



March 15, 2015

Contributed by Rohini Mathias

What is the common microscopic term that links the following conditions?
1. Hibernoma
2. Fabry's disease
3. Protothecosis
4. Measles


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Mulberry or morula

All the conditions mentioned above are characterized by 'mulberry' or 'morula' cells.

Hibernoma is a benign tumor consisting of adipocytes that resemble normal brown fat. Microscopically, it is characterized by large fat cells with a multivacuolated granular eosinophilic cytoplasm giving rise to the name 'mulberry', 'morula' or ping pong' cells

Protothecosis is a rare infection caused by the genus Prototheca, an achlorophyllic ubiquitous algae which is known to cause cutaneous lesions, disseminated or systemic disease and olecranon bursitis. On histology, dermal sporangia with endosporulation/(mulberry appearance) is seen, better demostrated with fungal stains like PAS and GMS. A typical feature of this endosporulation is the presence of a central round endospore with a corona of moulded endospores.

Fabry's disease is an X-linked lysosomal storage disorder characterized by excessive deposition of neutral glycosphingolipids in vascular endothelium of various organs, epithelial cells and smooth muscle cells. 'Mulberry' cells are fat laden epithelial cells and can be seen in urinary sediment of such patients. Mulberry like figures are also seen on electron microscopy in the eccrine glands.

Multinucleated giant cells (Warthin Finkeldy or mulberry cells) are seen in hyperplastic lymphoid tissue (lymph nodes, tonsils, adenoids, spleen, appendix and thymus in the prodromal phase of measles.


February 15, 2015

Contributed by Rohini Mathias

Spot the histological odd man out with a suitable reason to support your choice:

1. Fordyce spots

2. Muir - Torre syndrome

3. Pearly penile papules

4. Juxtaclavicular beaded lines

5. Steatocystoma multiplex


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Pearly penile papules

These are angiofibromas.
The other four choices have a link to the sebaceous gland.
Fordyce spots or Fordyce granules are ectopic sebaceous glands found in the vermilion border of the lips, cheeks, the glans or the vulva.
Muir-Torre syndrome is an autosomal dominant hereditary non-polyposis colorectal cancer syndrome associated with neoplasms of the skin, the most common being sebaceous tumours such as sebaceous carcinoma.
Juxtaclavicular beaded lines is an asymptomatic papular eruption over the neck and supraclavicular region characterized histologically by sebaceous gland hyperplasia in the immediate subepidermal zone.
Steatocystoma multiplex are multiple sebum containing dermal cysts, the walls of these cysts containing embedded lobules of sebaceous glands.



January 15, 2015

Contributed by Rohini Mathias

Which condition has all the features mentioned below?

1. Predilection for head and neck region

2. Perineural infiltration

3. Ductal differentiation, with downgrading of duct sizes in the deeper parts

4. Eosinophils in the infiltrate

5. CK-7, CK-15 and CD5 positive cells


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Microcystic adnexal carcinoma (MAC)

MAC, also referred to as malignant syringoma, sclerosing sweat duct carcinoma and sweat gland tumor with syringomatous features is a locally aggressive malignant sweat gland tumor with a predilection for the head and neck region, particularly the central face and upper lip.

Histologically, the tumor is poorly circumscribed occupying the dermis and subcutis and on occasion may invade deeper tissue. The superficial part is composed of keratocysts and small squamoid and basaloid nests with variable ductal differentiation. A typical finding is diminution in the size of nests and cysts in the deeper part of the tumor. Perineural invasion is common, which is not a feature in syringomas. Eosinophils are present particularly in areas of lesional clear cell change.

CD5 helps to differentiate MAC from morphea-like basal cell carcinomas and desmoplastic trichoepithelioma. CK-15 and CK-7, also positive in desmoplastic trichoepitheliomas, are negative in infiltrative basal cell carcinomas and squamous cell carcinomas.


December 15, 2014

Contributed by Rohini Mathias

Three tumors and an allergy…what could the link between these be?

1. Spongiotic vesicular dermatitis

2. Rhabdomyosarcoma

3. Squamous cell carcinoma of the cervix

4. Syringoma

With reference to microscopic features, what is the descriptive term common to the above conditions?


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Tadpole is the common descriptive term

In 1983, Pariser reported the usefulness of a Tzanck smear in the diagnosis of spongiotic vesicular dermatitis and concluded that the presence of at least 10 epidermal cells having a 'tadpole' like shape per x100 field was a reliable marker of in this condition.
The cell of origin of a rhabdomyosarcoma, the rhabdomyoblast has an eosinophilic granular cytoplasm and may at times be elongated, hence the name strap cells or tadpole cells.
Tadpole shaped cells are also described in squamous cell carcinoma of the cervix and are also found in an unstained urinary sediment in squamous cell carcinoma of the bladder.
In syringomas, the ductal structures at times have comma-like tails giving them a 'tadpole' configuration.



November 15, 2014

Contributed by Rohini Mathias

It may be invisible at first says the book,
But those dilated eccrine ducts deserve a second look,
Do take that biopsy at the appropriate time,
Else all will be wasted, and this isn't just a rhyme!
So immerse your hand in water little girl,
Let your diagnosis unfurl!

Which is the disease being talked about here?


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Aquagenic palmoplantar keratoderma

Aquagenic palmoplantar keratoderma (transient aquagenic hyperwrinkling/ aquagenic syringeal acrokeratoderma) is predominantly an acquired sporadic condition which mainly affects adolescents and females. It may also be associated with cystic fibrosis.
Clinically it is characterized by edema with wrinkling of the palms and soles, pruritus and whitish papules on contact with water (hand in bucket sign). The most opportune time for a biopsy is after contact with water as there are no pathological changes when the biopsy is taken from dry lesion-free skin.
Histologically, it may appear as an invisible dermatosis but careful scrutiny reveals ortho-hyperkeratosis with acanthosis and spongiosis. A rather consistent finding is the dilatation of eccrine acrosyringia.



October 15, 2014

Contributed by Rohini Mathias

Histologically, who is the odd man out...and why?

1. Sclerema neonatorum

2. Pancreatic panniculitis

3. Post-steroid panniculitis

4. Subcutaneous fat necrosis of newborn


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Pancreatic panniculitis

All the conditions listed (subcutaneous fat necrosis of the newborn, sclerema neonatorum, post-steroid panniculitis and pancreatic panniculitis) histogically present as lobular panniculitis. However, all of these with the exception of pancreatic panniculitis are associated with deposition of needle shaped crystals within adipocytes which appear as radially arranged clefts. Pancreatic or enzymic panniculitis is characterized by necrosis within fat lobules of the panniculus resulting in 'ghosts' of lipocytes, a granulomatous infiltrate with Langhans giant cells and calcification.


September 15, 2014

Contributed by Rohini Mathias

During immunosuppression I choose to surface...
Lots of plasma cells and histiocytes is what you see....
I take up Perls, Alizarin red and PAS,
That is how you will diagnose me!

a) What is the condition?
b) What are these histiocytes called?


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b)Von Hansemann cells

Malakoplakia is a chronic inflammatory disorder predominantly affecting the urogenital tract with the skin (vulva and perianal region) being rarely involved. It is mainly seen in the setting of immunosuppression and is believed to be due to defective phagolysosomal activity of macrophages resulting in an inadequate intracellular destruction of phagocytosed bacteria, particularly E.coli. Cutaneous lesions may show varied manifestation: papules, plaques, nodules, abscesses, fistulae, ulcers and polypoid masses.

Histologically, it is characterized by sheets of closely packed macrophages (Von Hansemann cells) which have a foamy cytoplasm and an eccentric rounded hyperchromatic nucleus. Michaelis-Gutmann bodies refer to the basophilic, concentric laminated inclusions within some of these macrophages. These cells stain positive with PAS, iron and calcium stains. Scattered lymphocytes and plasma cells are also seen.


August 15, 2014

Contributed by Rohini Mathias

Here are histological descriptions of 3 different cutaneous entities.

1. Collection of bipolar and dendritic melanocytes in the interstices of dermal collagen, tending to concentrate around appendages
2. Histologic pattern characterized by sharply defined intraepidermal nests of morphologically different cells
3. Focal loss of elastic fibres with normal collagen preceded by an inflammatory lesion

What is the 'name' common to these three?


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The 'name' common to the 3 histological descriptions is 'Jadassohn'. Joseph Jadassohn was a noted German dermatologist and a pioneer in allergology. Several diseases/ entities have been named eponymously after him.

1. Borst-Jadassohn phenomenon is a histological pattern characterized by sharply defined intraepidermal nests of basaloid to epithelioid cells seen in conditions such as clonal seborrheic keratosis, actinic keratosis, Bowen's disease and hidroacanthoma simplex.

2. Jadassohn -Tieche nevus, another name for a common blue nevus, is histologically characterized by collection of bipolar and dendritic melanocytes in the interstices of dermal collagen, tending to concentrate around appendages and neurovascular bundles.

3. Jadassohn Pellizzari type of anetoderma is a variant of primary idiopathic anetoderma where the anetoderma is preceded by inflammatory changes in contrast to the Schweninger-Buzzi type which has a non-inflammatory onset. This classification though, is only of historical interest.


July 15, 2014

Contributed by Rohini Mathias

Sew up the following clues together to crack this one…what’s your final diagnosis?

1. Gray horses
2. Black with occasional satellites
3. Dendritic and epithelioid cells
4. Predominantly dermal and occasionally deeper extension
5. Adnexotropic


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Equine melanoma/ Animal-type melanoma/ Pigmented epithelioid melanocytoma

This is a rare variant of malignant melanoma initially described in gray horses. Clinically, it presents as a well-circumscribed bluish-black nodule or plaque, predominantly located on the scalp and the limbs. Satellite lesions are relatively common. It generally appears de novo. Mortality rates are lower than other melanomas though several instances of nodal and distant metastasis have been reported.

Histologic features include heavily pigmented dendritic and epithelioid cells occupying the full thickness of the dermis and occasionally extending into the subcutis with infiltration of adnexal structures. Histological differentials include nodular melanoma, malignant blue nevus, deep penetrating nevus and metastatic melanoma.


June 15, 2014

Contributed by Rohini Mathias

There's a lot of lipid everywhere you see,
Be it in the keratinocyte or the Jordan's anomaly....
Some are born in hot wax or erythrodermic,
but peripheral nerves, they aren't so thick...
Inherited as an autosomal recessive trait,
A retinoid and dietary restrictions may improve this child's fate!

Identify the disease in the riddle....


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Chanarin Dorfman syndrome (Neutral lipid storage disease)

This autosomal recessive condition occurs due to the inability to breakdown endogenous triglycerides resulting in its consequent accumulation in various tissues and organs. It is characterized by ichthyosis which usually manifests at birth as a collodion baby or erythroderma, along with other systemic features such as hepatosplenomegaly, myopathy, cataracts and deafness.

A typical feature on light microscopy is the presence of lipid droplets in circulating polymorphs and monocytes (Jordans anomaly). Similar lipid droplets are also encountered in biopsies of the muscle and liver. Jordans anomaly may also be seen in Refsums disease, another ichthyotic disorder, however peripheral nerve thickening is a characteristic feature in the latter. Treatment includes emollients, systemic retinoids and possibly dietary restriction of long chain fatty acids.


May 18, 2014

Contributed by Rohini Mathias

Which among the following features does not fit into the 'Last Week's Sign' ?

1.       Parakeratosis overlying basket-weave orthokeratosis
2.       Mild epidermal hyperplasia
3.       Numerous necrotic keratinocytes
4.       Mild dermal inflammation


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Necrotic keratinocytes

Last week’s sign refers to a fading dermatosis, a dermatosis no longer active but was presumably so, a few days earlier. The feature that does not fit in is the presence of numerous necrotic keratinocytes.



April 15, 2014

Contributed by Rohini Mathias

Fish out the red herring and give a reason for your choice.

a.       Rheumatoid vasculitis
b.       Granuloma annulare
c.       Wegeners  granulomatosis
d.       Necrobiotic xanthogranuloma


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Necrobiotic xanthogranuloma

All the above mentioned conditions are collagenolytic (necrobiotic) granulomas which may be classified into 'blue' granulomas where the necrobiotic area stains basophilic due to the presence of mucin and 'red' granulomas which stain eosinophilic due to the presence of fibrin, eosinophils and flame figures. 'Blue' granulomas include granuloma annulare, Wegeners granulomatosis and rheumatoid vasculitis while 'red' granulomas include necrobiosis lipoidica, rheumatoid nodule, pseudorheumatoid nodules, necrobiotic xanthogranuloma, Wells syndrome and Churg Strauss syndrome.



March 15, 2014

Contributed by Rohini Mathias

People say I’m ‘3’ faced…but I’d best describe myself as ‘dimorphic’ ,
‘Roses’ are my favorite, but better beware of that thorn prick!
I prefer ‘cigars’ to cigarettes and astronomy intrigues me…
Microscopically I can create a cocktail!

Who am I?


Click to show/hide the answer

Sporothrix schenckii

This etiological agent of sporotrichosis (rose-pickers disease) is a dimorphic fungus. It clinically presents in 3 main ways: localized/fixed, lymphangitic/sporotrichoid and disseminated/systemic disease with the sporotrichoid presentation being most common. In the localized variant, several types of granulomas (tuberculoid, histiocytic, suppurative) may be found in the dermis. Cigar bodies represent the elongated yeast like form of the fungus and when these yeast forms are surrounded by eosinophilic hyaline ray like processes they are referred to as ‘sporothrix asteroid’ (see image), usually seen in the centre of suppurative granulomas.


February 15, 2014

Contributed by Rohini Mathias

What is the common descriptive term used in the microscopic findings of the following conditions?
a. Ochronosis
b. Pityriasis versicolor
c. Spitz nevus


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In ochronosis, both alkaptonuria and acquired, the ochronotic pigment on H & E staining takes up an ochre colour. It is found deposited within collagen bundles causing homogenisation and swelling of the collagen bundles, an appearance referred to as 'banana figures' or 'banana shaped bodies'.
The short hyphae and clusters of the yeast form of the Malassezia species on microscopy is called 'banana and grapes', more often referred to as 'spaghetti and meat ball' appearance.
The elongated nests of nevus cells in a Spitz nevus are sometimes found to hang down the rete ridges giving it an appearance of 'hanging bananas' or 'bunches of bananas'!



January 15, 2014

Rajalakshmi T, Inchara YK

january mindbender



1. If you want to get rid of this without a hitch, treat the baby and the grandpa for this itch.
4. Foamy, foamy in a sheath, seen in the midst like a wreath
8. Cells around a centre, pink or blue, Gran Ann is your clue
9. Schaumann and Asteroid in their cosy nests, skin deep goes this test
11. Many needles in this haystack, pain in the toes keeps coming back
12. Princess of Prussia, of royal blue blood

2. Cells undergone apoptosis, in this band-like dermatosis
3. What’s your email _ _?
5. Papules and pustules close to hair, spectacled cells everywhere
6. Virchow had a Mexican feast, thrombi in the vessels - how neat!
7. Bees buzzing in Rapunzel’s hair, caused her to exclaim in despair.
10. Rafa grips this like a winner; bumps in the skull, marrow and the liver


Click to show/hide the answer

jan mmb answer


December 15, 2013

Spot the odd one out:
a) Henoch-Schonlein purpura
b) Atrophie blanche
c) Finkelstein’s disease
d) Granuloma faciale


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Atrophie blanche

Atrophie blanche represents healed lesions of livedo vasculitis. The remaining three are expressions of leucocytoclastic vasculitis (LCV).
Fully developed LCV is diagnosed on histopathology on the basis of fibrin in vessel walls with or without thrombi, perivascular infiltrates and nuclear dust.
Henoch-Schonlein purpura is LCV with deposits of IgA in the vessels, usually seen in children. Extracutaneous manifestations are frequent, in the form of abdominal pain, haematuria and joint pains. Finkelstein’s disease, also known as acute haemorrhagic edema of infancy , is LCV that presents as purpuric lesions/plaques on the face and extremities of infants. Granuloma faciale presents as plaques/nodules on the face. Microscopically, it shows LCV with extensive dermal fibrosis, often in a storiform fashion and is not a granulomatous disorder. Erythema elevatum diutinum is its twin in a different anatomic location, the extremities.
Atrophie blanche is typified by depressed white scars on the legs, which represents healed livedo vasculitis. Livedo vasculitis is characterised by fibrin and thrombi often in the same vessel and accompanying lymphocytic infiltrates. Infarction and necrosis of the epidermis occur and finally lead to sclerosis and loss of pigmentation.



November 15, 2013

In a skin eruption of short duration, all the following features suggest a drug-related cause except:
a) Basket-woven orthokeratosis
b) Extravasated red cells
c) Wiry collagen in the papillary dermis
d) Many necrotic keratinocytes
e) Dermal oedema

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Wiry collagen in the papillary dermis

Normal basket-woven orthokeratosis, dermal oedema and extravasated RBCs are signs of acuteness in a lesion. Necrotic keratinocytes are usually abundant and may be seen at all levels of the epidermis. These are usually accompanied by extensive vacuolar interface dermatitis, the commonest histopathologic pattern of a drug eruption.
Wiry collagen bundles in the papillary dermis are often seen in mycosis fungoides, pityriasis lichenoides chronica and lichenoid purpura. These are seen along with a lichenoid infiltrate of lymphocytes and reflect the long-standing nature of the process.
Drug eruptions can display a multitude of histopathologic patterns. When one encounters several patterns within a single biopsy specimen or features that do not correspond to any known disease, it is reasonable to assume that the culprit is a drug and proceed accordingly.


October 15, 2013

Which two tumors are distinguished by their expression patterns of the combination of the immunohistochemical markers Cytokeratin 20, CD10 and Androgen receptors?
a) Trichoblastoma and Trichoepithelioma
b) Proliferating tricholemmal tumor and Squamous cell carcinoma
c) Trichoepithelioma and Basal cell carcinoma
d) Basal cell carcinoma and Squamous cell carcinoma

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Trichoepithelioma and Basal cell carcinoma

Both trichoepithelioma and basal cell carcinoma (BCC) show trichoblastic i.e. hair follicle differentiation; the former being benign and the latter, malignant. It is difficult to differentiate the two based on morphology alone, the problem being magnified in distinguishing desmoplastic trichoepithelioma from morphea-like BCC.
Cytokeratin 20 is a marker for Merkel cells, which are normally present in the basal layers of the epidermis and hair follicles. It has been demonstrated that CK 20 positive cells are seen in benign tumors with trichoblastic differentiation and not in malignant ones. Androgen receptor expression is seen in most BCCs, but not in trichoepitheliomas. CD10 shows stromal reactivity in trichoepitheliomas, highlighting the “germ and papilla” structures, which are diagnostic. In BCC, CD10 is expressed only by the neoplastic cells.
In summary, cytokeratin 20, CD10 and androgen receptors are useful in distinguishing between benign and malignant trichoblastic tumors.



September 15, 2013

A 45-year-old lady presented with blisters on her limbs. Histopathology showed a cell-poor subepidermal blister with a few dermal neutrophils. Direct immunofluorescence showed deposits of IgG and C3 in a BMZ pattern. Indirect IF on salt-split skin showed deposits localised to the floor of the split.
Which of the following autoantibodies is responsible for these findings and what is the disease?
a) anti BP 230
b) anti BP 180
c) anti laminin gamma 1
d) anti LAD 1

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Anti laminin gamma 1, seen in anti laminin gamma 1/anti p200 pemphigoid

Anti laminin gamma 1 has been identified as the target antigen in the rare variant of bullous pemphigoid (BP), called anti Laminin gamma 1 or anti-p200 pemphigoid. Classic pemphigoid is characterised by antibodies to BP 180 and 230, which show up as IgG and C3 deposits in a basement membrane zone (BMZ) pattern and localise to the roof of the blister on indirect IF. In contrast, anti-p200 pemphigoid binds to the floor of the split, similar to epidermolysis bullosa acquisita and may be mislabelled as such. Distinction of these two diseases requires immunoblotting. Anti LAD1 is responsible for linear IgA disease.


August 15, 2013

I am characterised by dilated infundibula with plugging. Sometimes, I also show cornoid lamellae. But, I am best known for my foamy friends who keep me company around the plugs.

Who am I?

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Fox-Fordyce disease or Apocrine Miliaria

Foamy histiocytes within the dermis are seen in diverse conditions such as xanthomas, xanthogranulomas and lepromatous leprosy. However, the presence of foamy histiocytes preferentially around dilated infundibula is seen only in Fox-Fordyce disease. Spongiosis is also seen in the infundibulum. Cornoid lamellae, deemed to be characteristic of porokeratosis, can also be seen in this condition.


July 15, 2013

I was spotted in the land of the rising sun in 1971. I have a net, but the itching is no fun. Neutrophils flood my epidermis, unlike my roti-hater friend who houses them in the dermis.

Which disease am I?

Click to show/hide the answer

Prurigo pigmentosa

The disease was first described by Nagashima in Japan in 1971. It is characterised by intensely itchy papulovesicles on the trunk and heals with net-like pigmentation. Histologically, it is characterised by a dense superficial dermal infiltrate of neutrophils that ascend to the epidermis and form abscesses. There is also accompanying spongiosis and ballooning. Later lesions contain dermal melanophages. The important differential diagnosis is dermatitis herpetiformis, in which the neutrophils are confined to the tips of dermal papillae and do not involve the epidermis.



June 15, 2013

In which condition do you find cystic sebaceous carcinomas?

Click here for the answer.


May 15, 2013

Which disease is characterised by a paranuclear dot pattern of staining with CK20?

Click here for the answer.


April 15, 2013

Which disease shows a chicken-wire pattern along with basement membrane staining on direct immunofluorescence?

Click here for the answer.


March 15, 2013

Which condition is the sandwich sign a clue to?

Click here for the answer.


February 15, 2013

Which disease is characterised by the checkerboard sign?

Click here for the answer.