Evaluation of large clinically atypical vulvar pigmentation with RCM: atypical melanosis or early melanoma?

BACKGROUND: Vulvar melanosis can occasionally be clinically challenging by mimicking an early melanoma. OBJECTIVE: To report our experience of initial evaluation and follow-up in this peculiar subset of vulvar melanosis using reflectance confocal microscopy (RCM). METHODS: We retrospectively evaluated 18 consecutive cases referred for atypical vulvar pigmentation or for which melanoma was considered and that underwent both RCM examination and histopathological assessment. In 13 cases with available dermoscopic pictures, RCM classification was compared to dermoscopic diagnosis, and in all cases, the density of melanocytes was evaluated on biopsies using MelanA immunostaining. RESULTS: Among the 18 atypical pigmented lesions, 17 vulvar melanosis and one melanoma were histologically determined. RCM concluded a benign vulvar melanosis in 10 of 17 cases, whereas dermoscopy did so in three of 12 cases. RCM identified the only early malignant lentiginous melanoma. In several cases of vulvar melanosis, RCM could identify foci of melanocytic hyperplasia in an otherwise benign pattern. CONCLUSIONS: In this clinically and dermoscopically challenging subset of vulvar pigmentations, RCM appears relevant for initial extensive evaluation, especially to target initial biopsy sampling, and to perform non-invasive monitoring of foci of melanocytic hyperplasia.

Mucosal melanoma: clinical, histological and c-kit gene mutational profile of 86 French cases.

BACKGROUND: Mucosal melanomas are rare and highly aggressive tumours. Few studies evaluated mucosal melanomas of locations other than the head and neck region, and other than those of the Asian population. OBJECTIVES: The objective of this study was to analyse the clinical and histological features, as well as the mutational status of c-kit and b-raf gene of mucosal melanoma in any localization in a French series. METHODS: We investigated clinical (sex, age, performance status, survival, treatment of the patients and lack of pigmentation of the tumours) and histopathological features (ulceration, Breslow's index, mitotic rate), as well as the mutational status of c-kit and b-raf of 86 mucosal melanomas diagnosed in 15 years in four French University Hospitals. RESULTS: Most melanomas affected women (72%) and the genital region (46.5%). A fifth of melanomas were amelanotic. 81% of melanomas had a Breslow's index ≥1, whereas all glans melanomas, and most vulvar melanomas had a Breslow index ≤1 mm. Overall survival was 54% at 3 years; 11.6% of the 43 tested mucosal melanomas were c-kit-mutated while the 15 tested genital melanomas were not. The c-kit gene mutation did not influence the overall survival. Age ≥ 50, amelanotic type and performance status ≥1 were not poor prognostic factors in our series. CONCLUSION: This study confirmed that mucosal melanomas are rare and could be difficult to diagnose being often amelanotic and in hidden sites. Most melanomas were thick at the diagnosis, but glans and vulvar melanomas were thinner probably because of their greater visibility. The frequency of the c-kit mutation varied depending on the initial tumour site. In our series, the prognosis was poor, independently from c-kit mutations and the patient's general health and age. The presence of metastasis at diagnosis was associated with a worse prognosis indicating the importance of an early diagnosis.

Reflectance confocal microscopy features of acral lentiginous melanoma: a comparative study with acral nevi.

BACKGROUND: Acral lentiginous melanoma (ALM) can be difficult to differentiate from acral nevus. Reflectance confocal microscopy (RCM) is widely used for the diagnosis of melanocytic tumours, but the RCM features of ALM and acral nevus have not been described yet. OBJECTIVE: To determine the RCM features of ALM and acral nevus, and their correlation with clinical and histological characteristics. METHODS: Retrospective study of 17 cases of ALM and 26 acral nevi. RESULTS: Pagetoid cells were present in all ALMs with a visible epidermis and in three nevi. A proliferation of atypical melanocytes at the dermal-epidermal junction (DEJ) and/or in the dermis was visible in nine ALMs but not in nevi. The histopathological examination of initial skin biopsies was unable to diagnose ALM in four cases, differing from RCM that could identify malignant tumour cells by exploring the whole lesions. CONCLUSION: Reflectance confocal microscopy can help in the differentiation of ALM and acral nevus, and to guide the biopsy.

Identification of a soft tissue filler by ex vivo confocal microscopy and Raman spectroscopy in a case of adverse reaction to the filler.

BACKGROUND: Soft tissue fillers are usually identified in the skin using the conventional histopathologic examination. Ex vivo RCM has been used in one case and Raman spectroscopy (RS), which has been recently applied for the identification of skin foreign bodies, has never been employed for fillers. We report the use of both these new techniques, ex vivo RCM and RS, to confirm the diagnosis of adverse reaction to a soft tissue filler and to identify its composition. METHODS: We excised a skin nodule suspicious of adverse reaction to soft tissue filler, and we performed an ex vivo reflectance confocal microscopy (RCM) and an histopathologic examination, followed by a RS analysis. RESULTS: Ex vivo RCM showed numerous hypo-reflective microspheres in the dermis that corresponded to rounded vacuoles at histopathologic examination, suggestive of polymethylmethacrylate (PMMA). RS showed a series of peaks at 600, 813, 970 1252, 1450, 1728, and 2951 cm(-1) in correspondence to the microspheres, confirming the presence of PMMA. CONCLUSION: These results suggest that ex vivo RCM and RS are additional tools to conventional histopathologic examination to characterize soft tissue fillers in case of adverse reaction. RCM has the advantage compared with the histopathologic examination that can be extemporaneously performed on a fresh surgical specimen. RS allow a precise chemical identification of the filler.

Confocal microscopy for healthy and pathological nail.

Nail diseases are often annoying for the patient and diagnostically challenging for dermatologists. New imaging techniques are of high interest in the diagnosis of nail disorders to reduce the number of nail biopsies. Confocal microscopy is a high-resolution emerging imaging technique that can be used to explore the entire body surface, including skin, mucosa, hair and nails. A systematic review of the literature concerning the use of confocal microscopy for the study of either healthy or pathological nail has been performed to evaluate the current use of this technique and possible future applications. Confocal microscopy is particularly suitable for nails because it allows a non-invasive in vivo examination of this sensitive body area, and nail plate transparency permits to image up to the nail bed with an easy identification of corneocytes. Confocal microscopy can play a role in the diagnosis of onychomycosis and melanonichia, and in the study of drug penetration through the nail plate. It could be used in the future as a non-invasive procedure for the investigation of different nail diseases, such as psoriasis and lichen planus. Further application could be the intra-operative ex vivo examination of nail specimens to outline tumour margins to assist surgery.