Could EMA and cytokeratin 7 be useful in distinguishing tricholemmal carcinoma from clear-cell squamous cell carcinoma? A case series from our department and a brief review of the literature

Tricholemmal carcinoma is a malignant cutaneous adnexal tumor showing outer root sheath differentiation, thought to be the malignant counterpart of trichilemmoma. Although the real existence of tricholemmal carcinoma continues to be a matter of debate, it has been introduced in the recently published 4th edition of World Health Organization classification of skin tumors. Herein, we evaluated whether immunohistochemistry (EMA, CK7, CK5/14, p63, p16, and Ber-EP4) supports tricholemmal carcinoma as a separate entity and whether it could be useful in this differential diagnosis. A total of 9 cases, 3 tricholemmal carcinomas and 6 clear-cell squamous cell carcinomas were evaluated on the basis of histological criteria suggested by the WHO. In our opinion, although these results need to be validated in larger series, they support tricholemmal carcinoma as a separate entity and suggest an immunohistochemical profile (clear-cell squamous cell carcinomas: EMA diffusely positive, CK7 negative; tricholemmal carcinoma: EMA negative, CK7 patchy or moderately positive) that could be useful for this differential diagnosis.

Malignant Melanoma Cells and Hair Follicles

OBJECTIVES

The extension of atypical melanocytes to the hair follicle, also termed melanoma folliculotropism, is poorly evaluated and its role is contradictory. We performed an observational study focusing on anatomical areas rich in follicles, such as the head and neck region.

METHODS

Primary head and neck melanomas diagnosed in the Melanoma Unit, Policlinic Sant'Orsola-Malpighi, University of Bologna were analyzed. Folliculotropism was evaluated with a quantitative and morphologic parameter. Statistical analyses were performed correlating patients' prognosis with folliculotropism and other clinical and histopathologic factors.

RESULTS

The study was carried out on a sample of 62 patients. The diffuse distribution (atypical melanocytes present in more than three contiguous follicular units) correlated with scalp localization, nodular subtype, higher Breslow thickness, and a poorer prognosis.

CONCLUSIONS

We believe that folliculotropism should be further investigated and reported by pathologists during the histologic diagnosis of melanoma.

Dermoscopic similarity is an independent predictor of BRAF mutational concordance in multiple melanomas

BACKGROUND

The association of clinical and dermoscopic features with BRAF mutational status has been poorly analysed in multiple primary melanomas (MPM).

OBJECTIVE

To investigate whether concordance of BRAF mutational status is associated with dermoscopic similarity in multiple melanomas of the same patient.

METHODS

Dermoscopic images and corresponding tissue sections of 124 melanomas from 62 patients with MPM were selected at four Italian Dermatology Departments. Similarity of dermoscopic appearance between multiple melanomas was evaluated according to the presence of the same prevalent dermoscopic feature. The BRAF^V600 mutational status was analysed with allele-specific TaqMan^TM assays or pyrosequencing. Spearman's correlation and univariate and multivariate regression analysis were used for statistical analysis.

RESULTS

A similar dermoscopic appearance was identified in 38.7% (24/62) of patients with MPM and was correlated with older age at first diagnosis (rho: 0.26; P: 0.042) and occurrence on sun-damaged skin (rho: 0.27; P: 0.037). The BRAF^V600 mutation was detected in 39.5% (49/124) of the tumors and a concordant BRAF mutational status between melanomas in 33/62 (53.2%) MPM patients. Dermoscopically similar melanomas showed 5.7-fold higher odds to be concordant for BRAF mutational status compared to dissimilar lesions (OR: 5.7; 95% CI 1.7-19.5; P: 0.005).

CONCLUSION

Dermoscopic similarity of multiple melanomas represents an independent clinical predictor of a concordant BRAF mutational status in MPM patients.

Interplay between small and long non-coding RNAs in cutaneous melanoma: a complex jigsaw puzzle with missing pieces

The incidence of cutaneous melanoma (CM) has increased in the past few decades. The biology of melanoma is characterized by a complex interaction between genetic, environmental and phenotypic factors. A greater understanding of the molecular mechanisms that promote melanoma cell growth and dissemination is crucial to improve diagnosis, prognostication, and treatment of CM. Both small and long non-coding RNAs (lncRNAs) have been identified to play a role in melanoma biology; microRNA and lncRNA expression is altered in transformed melanocytes and this in turn has functional effects on cell proliferation, apoptosis, invasion, metastasis, and immune response. Moreover, specific dysregulated ncRNAs were shown to have a diagnostic or prognostic role in melanoma and to drive the establishment of drug resistance. Here, we review the current literature on small and lncRNAs with a role in melanoma, with the aim of putting into some order this complex jigsaw puzzle.

Chilblain Lupus with Nail Involvement: A Case Report and a Brief Overview

Chilblain lupus erythematosus is a rare, chronic variant of cutaneous lupus erythematosus that occurs during cold or damp periods on the hands, fingers, or feet. It is often associated with other forms of cutaneous lupus and about 20% of patients develop systemic lupus erythematosus. Various medications have been put forward, including steroids, mycophenolate mofetil, calcium channel blockers, and hydroxychloroquine, but the symptoms do not remit completely.

An Ulcerated Reddish Nodule of the Chest: When You See, Think …

A 97-year-old man with a previous personal history of multiple nonmelanoma skin cancers presented with a fast-growing, ulcerated reddish nodule on his chest. The nodule was surgically removed, and hematoxylin and eosin stains of the specimen showed an asymmetrical, nonpigmented lesion with architectural and structural impairment, round cells with clear, whitish, foamy cytoplasm, multiple dermal mitoses and nuclear pleomorphism. Our first hypothesis was sebaceous carcinoma, a rare malignant neoplasm derived from epithelial cells showing sebaceous differentiation. A further histopathologic examination showed the presence of pigment in a few areas of the neoplasm. On immunohistochemical study, neoplastic cells were negative for wide-spectrum cytokeratin and diffusely positive for S-100, MART-1, and HMB-45 proteins. Our final diagnosis was nodular malignant melanoma (MM) with balloon epithelioid cells, a “bizarre” presentation of MM in vertical growth phase, mimicking metastatic and primary neoplasms of different lineage derivations.