Structural correlations between dermoscopic features of cutaneous melanomas and histopathology using transverse sections.

Interpretation of dermoscopic features of cutaneous melanoma is based on histologic description of perpendicular sections of the lesions that does not reflect the overview achieved by epiluminescence. We describe the utilization of transverse sections as a tool to define the histopathology of features that are the dermoscopic hallmarks of cutaneous melanoma. From a collection of 23 pigmented lesions with the dermoscopic diagnosis of cutaneous melanoma submitted for surgical excision we selected, from each specimen, one dermoscopic feature (black dots and globules, brown dots, blues dots and globules, depigmentation, broadened network, radial streams or pseudopods) that was sampled with a 4-mm punch (specimen) to obtain perpendicular and transverse sections. Using this strategy, it was possible to correlate the histopathology of all features that are often used as criteria for diagnostic dermoscopy. The black dots were pigmented neoplastic cells at the dermal-epidermal junction (DEJ) and within the epidermis in heavily pigmented columns. Similar findings were seen in brown dots, however there was slightly less pigment. No statistical difference was observed between brown dots and black dots regarding size, area and number of atypical cellnests. Blue dots correlated to melanophages, surrounding the superficial vascular plexus. Depigmentation was characterized by intense fibrosis of the papillary dermis. The pigmented network showed atypical pigmented or non-pigmented melanocytes at the DEJ and epidermis as well as heavily pigmented keratinocytes in the basal cell layer. The radial streaming and pseudopods had neoplastic cells in nests, a stratified growth pattern arranged in centrifugal linear extensions, resembling a arborescent branching. The results represented herein, are an important tool for understanding histopathological alterations responsible for dermoscopic features and for improving the efficacy of this diagnostic method.

Cutaneous melanoma in childhood and adolescence: retrospective study of 32 patients.

This study was performed to analyse the behaviour, risk factors, prognosis and evolution of cutaneous melanoma in childhood and adolescence treated in a single institution. A retrospective study was performed between 1980 and 2000 of patients aged 18 years or younger followed at the Hospital do Cancer de Sao Paulo, Brazil. Data included demographic status, risk factors, clinical and histopathological characteristics of the primary and metastatic lesions, stage and follow-up. Seventeen female (53.1%) and 15 male (46.9%) patients were studied. Twelve patients (37.5%) were aged 12 years or younger. The trunk was the most common location (14 patients; 43.8%). Five patients (15.6%) had giant congenital melanocytic naevus, three (9.4%) had xeroderma pigmentosum and one (3%) had dysplastic melanocytic naevus. Nodular melanoma was the most frequent histological type and 43.8% had a thickness of more than 4 mm. Five of the 32 patients (15.6%) were lost to follow-up and 15 (46.9%) were alive at the last year's follow-up, 11 (34.4%) without disease and four (12.5%) with active disease. The 5-year overall survival was 64.34%. An overall survival of 11.71% was found in patients with visceral metastasis with or without cutaneous and/or lymph node involvement, whereas the corresponding value was 90.48% (P value=0.0002) in patients with only cutaneous and/or lymph node metastasis. Cutaneous melanomas are uncommon in the young and are seldom diagnosed in the early stages, perhaps due to a reluctance to accept this diagnosis in this age group. Prevention and early stage diagnosis depend upon the recognition that this disease is present in the young.