Answers to Image of the Month 2018
Case contributed by Dr. Mithilesh Chandra
Hypertrophic lichen planus
Hypertrophic lichen planus presents as single or multiple, intensely pruritic verrucous plaques usually distributed on the legs. The lesions are often chronic and heal with hypo/ hyperpigmentation and scarring. Malignant transformation into verrucous carcinoma has been reported in longstanding cases.
On biopsy, the epidermis shows prominent hyperkeratosis, irregular acanthosis and hypergranulosis. Basal cell degeneration and civatte bodies are confined to the tips of rete ridges. Dermis shows band-like infiltrate comprising of lymphocytes and histiocytes. Longstanding lesions may show coexistent dermal fibrosis.
Case contributed by Dr. Meenakshi Batrani
Giant cell tumor of tendon sheath
Giant cell tumor of tendon sheath is a benign tumor with a predilection for dorsal surface of the fingers, in the vicinity of the distal interphalangeal joint. It presents in young and middle-aged adults as a slow growing, usually asymptomatic lesion, up to 3 cm in diameter. It is usually lobulated and attached to a tendon sheath or joint capsule. Multicentric lesions are rare. It is regarded as a variant of fibrous histiocytoma and as a tumor derived from mesenchymal cells.
On biopsy, the lesion is composed of sheets of histiocyte‐like cells with bland vesicular nuclei, intermixed with multinucleated giant cells, foamy cells, and scattered mononuclear inflammatory cells. In the sparsely cellular areas, the cells are plump and spindle shaped and set in a hyalinized stroma, whereas in the more cellular areas the cells are usually polygonal. Multinucleate giant cells with up to 60 or more nuclei are a characteristic feature. They are variable in number and haphazardly distributed. Hemosiderin deposition and cholesterol clefts are often seen.
Case contributed by Dr. V. Ramesh
Glomangioma or glomuvenous malformation
Glomuvenous malformation is an inherited, autosomal dominant, venous anomaly characterized by multifocal bluish purple lesions mainly located on the extremities. They are congenital, and never regress spontaneously. The clinical presentation is variableranging from inconspicuous, tiny, blue spots which are often grouped, to extensive or rarely, plaque-like lesions. They are raised, with a cobblestone appearance, slightly hyperkeratotic and usually painless. They are cutaneous and subcutaneous, and rarely involve the mucosa, deep muscles, joints or bones.
Histopathologically, glomuvenous malformations are poorly circumscribed, unencapsulated and consist of irregular ectatic vascular channels surrounded by small numbers of glomus cells. They demonstrate more prominent vessels and less conspicuous glomus cells than the glomus tumor proper. Glomus cells are rounded, regular cells with eosinophilic cytoplasm and darkly staining round to oval nuclei. The cells and vessels are embedded in a fibrous stroma.
Case contributed by Dr Meenakshi Batrani
Lichen striatus
Lichen striatus is a self-limiting, inflammatory dermatosis characterized by erythematous papules in a linear distribution along the lines of Blaschko. It usually occurs on the limbs in children aged 5-15 years and generally resolves over 6-12 months. Areas of post-inflammatory hypopigmentation may occur and persist longer. The etiology is incompletely understood, but 40% of the cases have a background of atopy.
The epidermis shows acanthosis, hyperkeratosis and focal parakeratosis with mild spongiosis and exocytosis of inflammatory cells. Small intraepidermal vesicles containing Langerhans cells are present in half the cases. Dyskeratotic cells are often present at all levels of the epidermis. The dermal papillae are mildly edematous. There is a lichenoid reaction pattern with an infiltrate of lymphocytes, histiocytes and melanophages occupying three or four adjacent dermal papillae. The infiltrate is usually less dense than in lichen planus and may extend around hair follicles or vessels in the midplexus. Eccrine extension of the infiltrate is often present.
Case contributed by Dr. Mithilesh Chandra
Tattoo inoculation lupus vulgaris
Tattooing predisposes to various infective and non-infective dermatoses. The infective disorders associated with tattooing include lupus vulgaris, viral warts, syphilis, leprosy, hepatitis B, hepatitis C, HIV, and molluscum contagiosum. Inoculation tuberculosis has been reported with various practices like piercing, sharing of infected syringes or needles, venepuncture, tooth extraction and tattooing. The pathogenesis of tattoo inoculation tuberculosis includes disruption of the skin barrier and unhygienic practices like sharing the same needle and ink, dilution of ink with tap water or saliva and topical preparations like soil, cowdung applied after the procedure, that might harbour mycobacteria. Although history, clinical features, histology, culture and Mantoux test help in the diagnosis, it is preferable to do PCR assay whenever possible.
On biopsy, there is hyperkeratosis, acanthosis, a dense inflammatory infiltrate comprising predominantly of mononuclear cells present throughout the dermis and foci of granulomatous infiltrate. Intercellular and intracellular tattoo pigment can be identified. Diagnosis of lupus vulgaris arising at the site of tattoo was made based on clinicopathological correlation. Several histological reactions to tattoo ink have been described including pseudolymphomatous, lichenoid, granulomatous, scleroderma or morphea-like, sarcoidal, granuloma annulare-like, pseudoepitheliomatous hyperplasia, allergic contact dermatitis and photoallergic reaction.
Case contributed by Dr. Geeti Khullar
Actinic keratosis
Actinic keratoses present clinically as circumscribed scaly erythematous lesions, usually less than 1 cm in diameter, on the sun-exposed skin of older individuals. They develop most often in those with a fair complexion. About 8–20% gradually transform into squamous cell carcinoma, if left untreated.
On biopsy, there is focal parakeratosis, with loss of the underlying granular layer and a slightly thickened epidermis with some irregular downward buds. Uncommonly, the epidermis is thinner than normal. There is variable loss of the normal orderly stratified arrangement of the epidermis; this is associated with cytological atypia of keratinocytes, which varies from slight to extreme. There is often a sharp border between the normal epidermis of the acrotrichia and acrosyringia and the parakeratotic atypical epithelium of the keratosis. The dermal changes include actinic elastosis and a variable, but usually mild, chronic inflammatory cell infiltrate. Variants include hyperplastic, atrophic, lichenoid, pigmented, bowenoid and acantholytic forms.
Case contributed by Dr. Geeti Khullar
Juvenile xanthogranuloma
Juvenile xanthogranuloma (JXG) is a benign proliferative disorder of histiocytes occurring in early infancy and childhood that spontaneously regresses. It is the commonest of the non‐ Langerhans cell histiocytoses. It is suggested that dermal dendrocytes are the precursor cells in JXG. Clinically, it presents with single (most common) to multiple reddish- brown to yellow papules or nodules with a predilection for the face, head and neck, followed by upper torso, upper and lower extremities. Systemic involvement occurs in 4% of children, involving the liver, spleen, lung, central nervous system and eye.
Biopsy reveals a nodular, poorly demarcated dense infiltrate of small histiocytes involving the dermis and sometimes the upper subcutis. The cells are polygonal or spindle-shaped and plump, and have indistinct cytoplasmic borders. Whereas early lesions are fairly monomorphous, with inconspicuous foam cells, mature lesions contain foamy histiocytes and varying number of Touton giant cells. There are also scattered lymphocytes and neutrophils, rare plasma cells and eosinophils. Lesions of longer duration show interstitial fibrosis and proliferating fibroblasts. On immunohistochemistry, histiocytes are positive for factor XIIIa, CD68, CD163, CD14, fascin and negative for S-100 and CD1a.
Case contributed by Dr Mithilesh Chandra
Porocarcinoma
Porocarcinoma is a malignant tumor arising from intraepidermal portion of eccrine ducts.The tumor arises from a pre‐existing benign eccrine poroma or hidraacanthoma simplex or may even develop de-novo. It occurs at all ages, although there is a predilection for older individuals. Acral locations, particularly the lower limbs, are favored. It presents as verrucous plaques or polypoid growths which may ulcerate or sometimes bleed with minor trauma. Pigmented variants, due to melanocyte colonization, are uncommon and can mimic melanoma. Local recurrence is seen in 17% of cases. Regional lymph node metastases and systemic metastases occur in 19% and 11% of patients, respectively.
The tumor is asymmetrical with an infiltrative growth pattern and multiple attachments to the epidermis. The intraepidermal component is composed of nests and islands of small basaloid cells, sharply demarcated from the adjacent keratinocytes. Broad anastomosing cords and solid columns and nests of large cells extend into the dermis and subcutaneous fat. Clear cell areas, squamous differentiation, melanin pigment, and focal necrosis may be present in the dermal nests. Ductal structures are also found. These may be demonstrated by the use of immunohistochemical stains for carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). A benign component of poroma or hidroacanthoma simplex may be present in 10% of the cases.Tumor with only intra-epidermal component is known as porocarcinoma in-situ.
Case contributed by Dr Mithilesh Chandra
Steatocystoma multiplex
Steatocystoma multiplex is characterized by multiple yellowish to skin-colored papules or cysts, with a predilection for the neck, chest and axillae. The cysts usually present in adolescents as asymptomatic lesions, but infected cysts (steatocystoma multiplex suppurativum) may be painful. It is occasionally associated with type 2 pachyonychia congenita. Mutations in the Ia domain of keratin 17 (K17) gene have been found in this syndrome. Steatocystoma multiplex is mostly sporadic, but familial cases with autosomal dominant inheritance are described. In some families with clinically and histologically typical steatocystoma multiplex, mutations in the K17 gene are found.
The lining of the dermal cysts is usually undulating due to collapse of the cyst. It is composed of stratified squamous epithelium, only a few cells thick and without a granular layer. The characteristic feature is the presence of sebaceous glands of varying size in or adjacent to the wall. A cord of epithelial cells connects the cyst with the epidermis, but this may not be seen in the plane of section. One pilar unit is associated with each cyst, and the cyst may contain one or more lanugo hairs. Spherules formed by masses of erythrocytes in the presence of oil-containing substances have been reported in the lumen. In contrast, eruptive vellous hair cysts are lined by mature squamous cells with a granular layer and and are not associated with sebaceous glands. The lumen contains keratin and numerous transversely and obliquely sectioned vellus hair shafts. Hybrid cysts with features of both steatocystoma and vellus hair cysts are sometimes seen.
Case contributed by Dr Mithilesh Chandra
Angioleiomyoma
Angioleiomyoma is a benign subcutaneous or deep dermal tumor that arises from the smooth muscles of blood vessels, usually veins. It presents as a solitary slow-growing, painful nodule on the extremities.
The tumor is well circumscribed with a fibrous capsule. It is composed of smooth muscle present as interlacing bundles between numerous vascular channels. Most of the vessels have several layers of smooth muscle in their walls which often merges peripherally with the intervascular fascicles. Small slit-like channels are sometimes present. Most vessels have only scant and scattered elastic fibers in their walls.The stroma contains varying amounts of fibrous tissue, and in about a third of cases there is a sparse lymphocytic infiltrate. Myxoid change is quite common in the stroma. The tumor may have foci of cartilaginous or adipose metaplasia. Uncommon changes include thrombosis of vascular channels, focal calcification, stromal hemosiderin, and hyalinization of vessel walls. Three histological variants of angioleiomyoma are described: a solid type, in which smooth muscle bundles surround numerous small slit-like channels; a cavernous type, with dilated vascular channels, the walls of which are difficult to distinguish from the intervascular smooth muscle; and a venous type, with thick-walled vessels which are easily distinguished from the intervascular smooth muscle.
Case contributed by Dr Mithilesh Chandra
Lupus miliaris disseminatus faciei
Lupus miliaris disseminatus faciei (LMDF) is a granulomatous disorder predominantly involving the centro-facial area, including the region around the eyelids. It usually presents as multiple skin colored or yellowish brown papules and pustules, which heal to leave behind pock like scars. Although extrafacial involvement and a nodular morphology of lesions have been reported, these are very uncommon. It is most commonly seen in young adults.
Early lesions show superficial perivascular and periappendageal lymphocytic infiltrate with a few histiocytes and neutrophils. The characteristic feature is an area of dermal necrosis, described as caseation necrosis, surrounded by epithelioid histiocytes, multinucleate giant cells and lymphocytes. The granulomas appear related to ruptured pilosebaceous units. Late lesions show perifollicular fibrosis.
Case contributed by Dr Mithilesh Chandra
Granular cell tumor
Granular cell tumor is of neural derivation. Granularity of tumor cells is due to the accumulation of secondary lysosomes in the cytoplasm. Granular cell tumors are typically solitary, smaller than 3 cm, and located in the dermis or subcutis and less frequently in the submucosa, smooth muscle, or striated muscle. They are also found in the internal organs, particularly in the upper aerodigestive tract. Benign and malignant counterparts are known; the latter are rare, comprising fewer than 2% of all granular cell tumors. Most patients are middle-aged, with a peak incidence in the fourth to sixth decade of life. A slight female predominance exists. It is firm and round but with rather indefinite margins and sessile or pedunculated.
The tumor is composed of irregularly arranged sheets and nests of large polyhedral cells with a small central vesicular nucleus and abundant fine to coarsely granular eosinophilic cytoplasm. Large cytoplasmic globules surrounded by a clear halo (pustulo-ovoid bodies of Milian) are present. When these are extruded from cells and phagocytosed by histiocytes, they are termed angulate bodies. The cytoplasmic granules are PAS positive and diastase resistant. Cells infiltrate between collagen bundles and displace them. They surround the appendages and may extend into the arrector pili muscle. The tumor usually expresses S100 protein.