Answers to Image of the Month 2016
Case contributed by Dr Sudheer Arava
Follicular Dowling-Degos disease
Biopsy showed prominent thin finger like elongation of the rete ridges with increased basal cell pigmentation. There is thinning of the suprapapillary plate. Centre of the lesion shows a dilated hair follicle with similar findings. Dermis is unremarkable. There is no increase in the melanocytes.
Case contributed by Dr. Subhra Dhar
Paget's disease of breast
Infiltration of epidermis by the characteristic Paget's cells which are malignant glandular epithelial cells with enlarged hyperchromatic nuclei often having a discernible nucleoli. The cytoplasm is pale to clear and may even contain mucin. The cells do not form intercellular bridges with the adjacent prickle cells. Paget's cells are often located in the basal region of the epidermis where they may lie either as single cells or as clusters of cells forming gland like structures or nests. Because of shrinkage artefact, cells may appear to lie within intraepidermal lacunae. The underlying dermis shows variable telangiectasia and inflammation. An underlying invasive /in- situ ductal carcinoma is found in >90% of patients of Paget's disease.
Paget's disease of breast is often mistaken for benign skin conditions clinically as symptoms are like those of eczema. The lesions are scaly, crusty and associated with redness, itching and tingling sensation.
Case contributed by Dr Meenakshi Batrani & Dr Asha Kubba
Infantile digital fibromatosis (inclusion body fibromatosis), also known as Reye’s tumour.
Non-encapsulated dermal tumour composed of interlacing fascicles of myofibroblastic spindle cells and dense collagenous stroma. The hallmark finding is round or ovoid, eosinophilic, 3- to 10µm intra-cytoplasmic paranuclear inclusion bodies which stain red with the Masson trichrome stain (shown here) and purple with phosphotungstic acid-hematoxylin. On IHC, cells are positive for SMA (shown here), Calponin and Desmin.
It is a relatively rare disease with approximate prevalence of 2.5%. It is a benign, spontaneously regressing, fibrous tissue tumour of infancy and childhood that commonly appears in the first year of life and may be present at birth in one-third of cases. It has a tendency to local recurrence without bony invasion or metastasis. Single or multiple, firm reddish-pink slowly growing nodules, about 2 cm in size are present on the extensor aspects of the phalanges of the last four fingers or toes, sparing the thumb and great toe. Lesions are characteristically asymptomatic; if large, they may result in limited joint mobility and functional deformity of the digit.
Case contributed by Dr Inchara YK
Nodular hidradenoma
Section shows skin with a well-circumscribed, dermal based solid-cystic neoplasm which is vertically oriented. The neoplasm is composed of round to polygonal cells arranged in nests, sheets, papillae and tubules. These cells have a central, round nuclei and abundant clear to eosinophilic cytoplasm. Some cells have a plasmacytoid morphology. Intervening areas of hyalinisation noted. Foci of cystic change and haemorrhage are seen. There is no evidence of nuclear atypia/ mitosis / necrosis.
Hidradenoma is a rare, benign adnexal neoplasm presenting as an asymptomatic solitary papule or nodule. They have no predeliction for site/ age or sex. Contrary to earlier belief, these are mostly apocrine in nature. Architecturally, the neoplasm may be exo/endophytic, solid/cystic often with connection to the infundibula. Solid areas comprise of round to polygonal cells with tubules lined by double row of epithelial cells. Cystic areas show eosinophilic secretions. Cytologically, spectrum of differentiation of the epithelial cells may be noted such as clear cell, squamoid, mucinous, plasmacytoid and sebaceous. Differential diagnosis: Metastatic renal cell carcinoma to the skin also has clear cells, but the striking vascularity and absence of infundibular connection helps to differentiate.
Case contributed by Dr Gayatri R & Dr Inchara YK
Histoid leprosy
The epidermis is atrophic. A subepidermal clear zone is seen. The dermis shows a diffuse infiltrate composed of plump, spindle shaped cells arranged in storiform pattern admixed with foamy histiocytes and lymphocytes. No nerves are identified. The Fite stain showed numerous acid fast bacilli. These can be recognised even in the H&E stained section as negative images with a bluish hue within the histiocytes.
Histoid leprosy, a spindle cell lesion, is a close mimic of dermatofibroma. It was describe by Wade in 1963. It commonly involves extremities, back, buttocks and face. It is seen in patients who do not respond to MDT, treated irregularly or rarely, may be de novo. It differs from classic lepromatous leprosy by the presence of spindle shaped cells, which are also histiocytes. Dermatofibroma usually has keloidal collagen at the periphery, is not as well delineated and the Fite stain is negative.
Case submitted by Dr Rajalakshmi T
Glomangioma
The epidermis is unremarkable. The dermis shows a neoplasm comprising of many ectatic thin walled vessels surrounded by cells exhibiting round nuclei and moderate amount of granular eosinophilic cytoplasm. Mitotic figures are infrequent.
Glomangioma is the commonest variant of glomus tumor. In contrast to the solid nests of glomus cells in the latter, the former consists of layers of glomus cells surrounding dilated, cavernous vascular channels. They are also termed glomuvenous malformations by some.
Case submitted by Dr Inchara YK
Alopecia areata
Sections from scalp show hair follicles with the bulbs situated in the deep dermis, none are evident in the subcutis. They appear to be catagen follicles that are miniaturised. There is a moderate peri-bulbar lymphocytic infiltrate (swarm of bees) and peri-bulbar fibrosis. A single fibrous stela is seen, accompanied by lymphocytes. The epidermis and rest of the dermis are unremarkable.
The presence of an exclusive peri-bulbar lymphocytic infiltrate is virtually diagnostic for alopecia areata (AA), the density of which is variable. All follicles appear to be in the same stage of catagen, reflecting the time of assault by the lymphocytes.
In chronic/long-standing lesions, inflammation can be minimal or absent. Progressive miniaturisation of follicles may ensue, simulating androgenetic alopecia. Finally, only fibrous tracts (stelae) remain, that contain remnants of glassy catagenic basement membrane and melanophages.
Case submitted by Dr Mithilesh Chandra
Tubular apocrine adenoma
This is a benign dermal adnexal neoplasm of apocrine derivation, also called apocrine adenoma, tubular adenoma, tubulopapillary hidradenoma, papillary tubular adenoma. Most common location is scalp, typically in women. Associated with organoid nevus, nevus sebaceus of Jadassohn and syringocystadenoma papilliferum. Rarely occurs on nose, eyelid, leg, trunk, axilla, chest, external auditory meatus, cheek, vulva. Clinically asymptomatic, sometimes smooth, sometimes irregular, well-defined nodule.
It is a well circumscribed dermal neoplasm that may extend into subcutis. Lobular pattern of dermal and subcutaneous tubular apocrine structures often encased by a fibrous, sometimes hyalinized stroma. Lobules have dilated, variably sized tubules lined by two layers of epithelial cells. Decapitation secretion by apical layer. Cuboidal to columnar cells with eosinophilic cytoplasm and round bland nuclei. Often hyaline and clear cell change. May show cyst formation with papillae or pseudopapillae protruding into the lumen. Variable overlying epidermal hyperplasia. Rare connection with overlying epidermis.
Case submitted by Dr Rajalakshmi T
Granuloma faciale
Section shows flattened epidermis. The dermis shows a nodular and interstitial infiltrate of lymphocytes, neutrophils, few eosinophils and scant nuclear dust. Focal extravasated RBCs are noted. Prominent vasculature is noted with thin wiry short fascicles of collagen accompanied by fibrocytes. There is no fibrinoid necrosis of the vessel walls. Special stains performed: PAS and Fite stains showed no additional findings.
Granuloma faciale (GF) is a chronic expression of leucocytoclastic vasculitis ocurring on the face. Essentially, GF and Erythema elevatum diutinum (EED) are the same pathologic process, differing only by the anatomic site of occurrence. While GF occurs on the face, EED occurs on the extremities. They present as papules/ plaques or nodules and have a protracted course. Fully developed lesions show a nodular/ diffuse inflammatory infiltrate comprising of neutrophils, lymphocytes, eosinophils, plasma cells and a few histiocytes throughout the dermis accompanied by nuclear "dust". Prominent vasculature accompanied by short fascicles of wiry collagen and numerous fibrocytes are seen in the dermis. Fibrin is not demonstrable in the blood vessels unless it is an early lesion. In very late lesions histiocytes are prominent.Granuloma faciale is a misnomer as granulomas are not characteristic of this lesion (although it may be present in a rare instance). An ancient terminology for EED is "Extracellular cholesterosis" as some late lesions may show extracellular deposits of cholesterol. Another term which is no longer in vogue is "Toxic hyaline" used by some authors to describe the fibrin in the vessel walls of EED.
Case contributed by Dr Inchara YK and Dr Poonam Panjwani
Morphea
Section shows thickened and crowded collagen bundles in the dermis with a mild perivascular and periadnexal lymphocytic infiltrate with occasional plasma cells. The adnexal structures are pulled up and the epidermis is atrophic.
A good clue on scanning magnification is the "square" shape of the biopsy. Early lesions can show a significant amount of perivascular, interstitial infiltrate of plasma cells and lymphocytes (at times, eosinophils). Alterations in collagen may be subtle in such lesions, making them appear "pinker" than normal. In fully developed lesions, one appreciates the characteristic thickened, crowded collagen bundles, that also frequently extend to the subcutaneous septae. Nevertheless, the space between them is present, albeit narrowed. This is in contrast to the homogenization seen in lichen sclerosus et atrophicus, a superficial expression of morphea. In late stages (i.e. atrophoderma of Pacini and Pierini), the spaces are well seen, as the collagen fibres thin out.
The differentials include Scleredema adultorum of Buschke, which shows presence of increased dermal mucin and absence of inflammatory infiltrate and chronic GvHD.
It is important to understand the terms fibrosis and sclerosis. Fibrosis results from proliferation of fibrocytes, as seen in scars and keloids. In sclerosis, the spaces between collagen are obliterated, as in LSEA. Morphea does not satisfy either of the two definitions, although included under the category of fibrosing diseases. That is some food for thought!
Case contributed by Dr Inchara YK
Darier's disease
The epidermis shows multiple foci of suprabasal clefting with acantholytic cells in the spinous and granular layer. Several dyskeratotic cells are noted. Also noted are columns of parakeratosis. Focal downward proliferation of the epidermis is noted with a mild perivascular lymphocytic infiltrate in the dermis.
Darier's disease is a autosomal dominant genodermatosis named after a French dermatologist Ferdinand-Jean Darier. It usually presents during the second decade as dirty brown, rough surfaced, keratotic papules affecting the seborrheic regions and extensor surfaces. Histologic features are focal acantholysis with dyskeratotic cells, parakeratosis and intraepidermal clefts. The differential diagnosis include Grover's disease and warty dyskeratoma.
Grover's disease is an inflammatory process ocurring in adults over 40 years and affecting the V of the chest, thighs, flanks and thighs. Histologically, it shows spongiosis and acantholysis in the same focus. Often, in the same biopsy specimen one sees features of pemphigus, Hailey -Hailey disease, spongiosis with acantholysis and acantholysis with dyskeratosis. Tiny intraepidermal vesicles and eosinophils in the papillary dermis are common. Evidence of excoriation is often present.
Warty dyskeratoma is a solitary papule /nodule with an umbilicated centre affecting the head and neck of middle aged and elderly people. Histology reveals a cup shaped well circumscribed invaginating lesion characterised by suprabasilar clefting,acantholysis, dyskeratosis and a keratinous plug. Protruding into the lacunae are dermal villi covered by a basal layer of cells.