Asok Biswas

Inflammatory complications related to tattooing: a histopathological approach based on pattern analysis.

Abstract:Although tattooing is an ancient practice, its increasing popularity and social acceptance, variability of tattoo ink composition, sporadic reports of novel tattoo reactions and advances in the field of tattoo removal techniques make it a topic of immense interest among dermatologists and pathologists alike. Since effective legislation governing the tattoo industry is largely lacking in most regions of the world, it is important to recognize the range of tattoo-related complications from a dermatopathological perspective. Using a pattern-based approach, this review details the broad spectrum of inflammatory reactions, which may be encountered in adverse reactions associated with tattooing. Awareness of the range of inflammatory tattoo reactions is crucial as some of these patterns of inflammation can be associated with systemic disorders and others may serve as important clues for an underlying infective condition.

Endocrine mucin-producing sweat gland carcinoma: report of two cases of an under-recognized malignant neoplasm and review of the literature.

Abstract:Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare low-grade sweat gland carcinoma with a strong predilection to the eyelid region. It is histologically analogous to endocrine ductal carcinoma/solid papillary carcinoma of the breast and is characterized by a multinodular solid cystic mucinous tumor with immunoreactivity to neuroendocrine markers. Only 20 cases of this unusual tumor have been reported. We present the clinical and histopathologic findings of 2 new cases of EMPSGC and review the relevant literature. The histological differential diagnosis is discussed and attention drawn to the role of immunohistochemistry in clarifying the nosological position of EMPSGC within the spectrum of cutaneous mucinous neoplasms.

The Value of Skin Biopsy in Inflammatory Dermatoses

The skin biopsy is considered one of the most important tools in dermatology. Two primary reasons a clinician may perform a skin biopsy are either to establish a diagnosis or to evaluate therapy. The objective of this study was to critically assess the value of the skin biopsy as a diagnostic test for inflammatory dermatoses. One hundred consecutive skin biopsy specimens where an inflammatory dermatosis was queried were reviewed. To assess the diagnostic ability of the skin biopsy, the frequency with which a correct diagnosis was made based on histopathological analysis alone was recorded, that is, an initial “blind” diagnosis made without clinical data. Once this was recorded, the clinical history was provided and a posthistory diagnosis reached. The posthistory diagnosis was then compared with the final working diagnosis in the patient case notes. In 55% of cases, histology was able to provide a prehistory specific diagnosis. In 31% of cases, histology was not able to provide a specific diagnosis but could provide a differential diagnosis. In two thirds of these (20 of the 31 cases), the diagnosis was reached posthistory with clinicopathologic correlation. In 12% of cases, histology could only provide a pattern analysis, and in 2% of cases, only a descriptive report could be issued. In 13% of cases, the biopsy provided the final working diagnosis, which had not been considered clinically. The skin biopsy for inflammatory dermatoses is clearly a worthwhile investigative procedure. Prehistory blind histology based on microscopic data provided an accurate diagnosis correlating to the working diagnosis in 53% of cases. The diagnostic boundaries of dermatopathology are such that in an additional 25 cases (25%) a diagnosis was reached with aid of clinical data proving the importance of providing a well-thought-out differential diagnosis. Overall, in 78% of cases, histology with the aid of clinical information was able to provide an accurate diagnosis correlating to the working diagnosis.

Palisaded neutrophilic and granulomatous dermatitis in a child with type I diabetes mellitus and coeliac disease

SIR, A 10-year-old girl with type I diabetes mellitus and coeliac disease presented with a 2-month history of slightly tender, closely set erythematous papules forming a vague annular plaque on the dorsum of the left foot. Similar papules in a linear distribution were also seen on the lateral aspect of the right ankle. She was on long-term insulin treatment and her fasting glucose level was 16Æ2 mmol L (normal 4–8) and glycosylated haemoglobin level 10Æ2% (normal 4Æ0–6Æ0) at presentation. Circulating antipancreatic islet cell and anti-endomyseal IgA antibodies were present. The skin lesions on both sides resolved spontaneously within days of the initial consultation. An incisional biopsy from the lesion on the left foot showed a patchy interstitial infiltrate of histiocytes forming palisaded granulomas surrounding areas of degenerate collagen, neutrophils and nuclear debris (Fig. 1a). At the centre of the granulomas the appearances were very similar to leucocytoclastic vasculitis (Fig. 1b). No dermal mucin was apparent and plasma cells were very few in number. This combination of a necrobiotic granulomatous and vasculitic reaction pattern was consistent with a fully developed lesion of palisaded neutrophilic and granulomatous dermatitis (PNGD). Following a diagnosis of PNGD, she was evaluated by the rheumatologist to rule out an underlying connective tissue disorder. This was felt necessary because of the known association of PNGD with rheumatoid arthritis. There were no clinical abnormalities in the musculoskeletal system. Rheumatoid factor, antineutrophil cytoplasmic antibodies, antinuclear antibodies and antidouble-stranded DNA antibodies were negative. An extractable nuclear antigen screen was also negative. Serum immunoglobulin levels were within normal limits. Three months later, she presented with bilateral local recurrence composed of small erythematous papules arranged in a linear pattern over a 3-cm area (Fig. 2). These lesions improved considerably with better control of blood glucose levels through adjustments of insulin dosage, and no local or systemic treatment for the skin lesion was necessary. PNGD is a rare and unusual inflammatory dermatosis which is not very well characterized. In 1965 Dykman et al. reported an entity similar to PNGD in rheumatoid arthritis patients presenting with linear subcutaneous bands on the trunk. Finan and Winkelmann used the term ‘Churg–Strauss granuloma’ due to the histological similarity to the granulomas seen in Churg–Strauss disease. Smith et al. described papular lesions in rheumatoid arthritis showing features of leucocytoclastic vasculitis and palisading granulomas. Finan, in a letter to the editor, suggested that rheumatoid papule and Churg–Strauss granuloma were the same entity. Perhaps the most comprehensive morphological account of this condition was given by Chu et al. who also coined the name ‘palisaded neutrophilic and granulomatous dermatitis of immune complex disease’. The aetiopathogenesis of PNGD is unclear. The constant association of PNGD with various connective tissue disorders points towards the role of immunological mechanisms. Considering that both type I diabetes mellitus and coeliac disease are immunologically mediated, it is not surprising that they (a)

Cutaneous clear cell neoplasms: a histopathological reappraisal.

Abstract: Cutaneous clear cell neoplasms represent a heterogenous group of several primary and metastatic tumors with diverse histogenesis. Tumors with widespread clear cell change can seem strikingly similar under the microscope resulting in diagnostic difficulties. Although most cases are idiopathic, intracytoplasmic accumulation, artifact of tissue processing, and degenerative phenomenon have been cited as possible causes of clear cell change. An awareness of the various entities demonstrating this attribute, judicious use of ancillary techniques, and knowledge of the clinical setting are crucial to the accurate diagnosis. This review details the histological features of clear cell neoplasms of the skin with particular emphasis on the discriminating features.

Cornoid lamellation revisited: apropos of porokeratosis with emphasis on unusual clinicopathological variants.

Abstract:Porokeratosis is a family of several disorders characterized histologically by the presence of cornoid lamellae. The presence of cornoid lamellae represents an abnormal form of keratinization, which unifies all types of porokeratosis. A significant variation in lesional morphology can result from peculiarities involving the cornoid lamellae and changes related to epidermal hyperplasia and dermal inflammation. This diversity has led to the recognition of several unusual clinicopathological variants of porokeratosis in recent years. Cornoid lamellation, however, is not pathognomonic of porokeratosis and can be seen in some inflammatory and inherited cutaneous disorders and also as an incidental finding. Some of these conditions can be confused with an atypical presentation of porokeratosis and vice versa. An awareness of the broad morphological spectrum of porokeratosis is crucial to avoid missing the diagnosis when appearances are far from typical. This issue is critical in patient management given the potential premalignant nature of porokeratosis.

Mast cells in cutaneous tumors: innocent bystander or maestro conductor?

Evidence favoring a critical role for mast cells (MC) in cutaneous malignancies is conflicting.

Rhabdomyomatous Mesenchymal Hamartoma With Lentiginous Melanocytic Hyperplasia : An Inductive Phenomenon or Component of the Hamartoma?

Rhabdomyomatous mesenchymal hamartoma (RMH) is a rare cutaneous hamartoma characterized by abundant bundles of mature skeletal muscle fibers admixed with other mesenchymal elements. We report a case of RMH in a 7-month-old girl with associated lentiginous melanocytic hyperplasia. The melanocytic hyperplasia was not apparent clinically and was only evident on histological examination. Unlike a smooth muscle hamartoma, melanocytic abnormalities have never been described in the context of RMH. Though the exact significance of this observation is not clear, we speculate that the melanocytic hyperplasia could be related to an inductive phenomenon or constitute a part of the overall hamartomatous process. Careful attention to epidermal changes in future cases of RMH may help in understanding the significance of this association and refine our knowledge of the pathogenesis of RMH.

Cutaneous neoplasms with prominent Verocay body-like structures: the so-called "rippled pattern".

A striking appearance resulting from alternating areas of epithelial cell cords and stroma seen in some cutaneous adnexal neoplasms has been referred to as the “rippled pattern.” Histologically, this pattern may be indistinguishable from Verocay bodies described in schwannomas. A number of common and clinically diverse cutaneous neoplasms can be linked by the presence of this unusual growth pattern. The heterogeneous group of tumors that have been known to demonstrate this feature includes those with epithelial, adnexal, fibrohistiocytic, mesenchymal, and melanocytic lineage. The objective of this review is to alert the dermatopathologist to the range of neoplasms, which can potentially show this attribute, so that a misdiagnosis can be avoided.

Tumoral PD-L1 expression in desmoplastic melanoma is associated with depth of invasion, tumor-infiltrating CD8 cytotoxic lymphocytes and the mixed cytomorphological variant

Recently, patients with metastatic desmoplastic melanoma (DM) have been shown to respond more favorably to anti-PD1/PD-L1 therapy than other melanoma subtypes. Given this, we evaluated PD-L1/2 expression in primary DM samples and correlated these with subtype, CD8+ lymphocyte status, histopathological prognosticators, and select genetic alterations. Eighty-six (36 mixed DM, 50 pure DM) archival annotated samples met inclusion criteria and were immunohistochemically semiquantitatively evaluated. Per established criteria, for PD-L1/L2, cases with ⩾5% tumoral expression, and for CD8, cases with a predominantly peri/intratumoral CD8+ infiltrate were scored positive. Univariate analysis (chi-square and Wilcoxon) identified potential confounders and a nested case–control study was accomplished using multiple logistic regression. For PD-L1, 49% of cases were positive and 71% of cases with thickness >4 mm were positive; PD-L1 expression differed by median depth (3.29 mm, interquartile range=3.58 mm for PD-L1 positives vs 1.75 mm, interquartile range=2.04 mm for PD-L1 negatives, P=0.0002) and was linearly associated with increasing depth of invasion (P=0.0003). PD-L1-positive cases were more likely to display CD8+ lymphocytes (60 vs 28% P=0.0047).The presence of CD8+ lymphocytes correlated significantly with depth of invasion >1 mm (P=0.022). On multivariate analysis, PD-L1 was 6.14 × more likely to be expressed in mixed DM than pure DM (P=0.0131), CD8+ staining was 6.22 × more likely in PD-L1 positive cases than in PD-L1 negative (P=0.0118), and tumor depth was associated with greater odds of PD-L1 expression (OR=1.61, P=0.0181). PD-L2 expression was observed in 48% of cases but did not correlate with any variables. Correlation of tumoral PD-L1 with increased depth and CD8+ lymphocytes implicates the tumoral immune microenvironment with advancing disease in DM. Enhanced tumoral PD-L1 expression in the mixed cytomorphological variant provides an insight into the differential pathogenesis of the subtypes and suggests that these patients are likely better candidates for anti-PD/PD-L1 therapy.