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Atypical Melanocytes (atypical + melanocyte)
Selected AbstractsPseudoglandular-type melanoma: a rare melanoma variantJOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2008Mordechai M. Tarlow We describe a 64-year-old man with a primary nodular melanoma showing unusual histologic features. It consisted entirely of markedly atypical melanocytes arranged in a well-structured glandular pattern. These atypical melanocytes were positive for S-100. This is only the second report of such histology in melanoma, and to our knowledge, the first such case consisting entirely of these features. We review the literature on this rare variant of melanoma. [source] Melanoma associated with a dermatofibromaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 5 2007Bradley T. Kovach Background:, Dermatofibromas are common benign cutaneous fibrohistiocytic neoplasms, whereas melanomas are potentially aggressive malignancies. Differentiating these two entities can occasionally be difficult. Methods:, We report the case of a 56-year-old female presenting with a firm pink papule on the left thigh. Results:, Histopathology revealed atypical melanocytes in the epidermis and papillary dermis with numerous mitotic figures and intraepidermal pagetoid spread. Within the dermis was a poorly demarcated collection of epithelioid and spindled cells with intermixed keloidal collagen. The atypical melanocytes stained for MART-1 and S-100, whereas the underlying fibrohistiocytic tumor took up factor XIIIa immunostain, confirming the diagnosis of invasive malignant melanoma occurring in association with a dermatofibroma. Conclusions:, This case emphasizes the role of immunohistochemical stains in correctly diagnosing melanocytic and histiocytic neoplasms. [source] Subungual melanoma: Histological examination of 50 cases from early stage to bone invasionTHE JOURNAL OF DERMATOLOGY, Issue 11 2008Miki IZUMI ABSTRACT Subungual melanoma is a rare form of malignant melanoma. It is extremely difficult to differentiate it histologically from benign melanonychia striata or melanocytic nevus, especially in the early stage. We divided 50 cases of subungual melanoma into four groups according to clinical progress, and examined their histological findings in each respective stage. In the early stage (19 cases), atypical melanocytes were polygonal showing slight nuclear atypia with no mitoses at all. In six out of 19 cases (31.6%), the atypical melanocytes proliferated more in the hyponychium than in the nail matrix, and only very few in the nail bed. Periungual pigmentation (Hutchinson's sign) appeared from the early stage in almost all cases. With stage progression (middle stage, 13 cases; progressive stage, 13 cases; and bone invasive stage, five cases) the number of atypical melanocytes and their degree of nuclear atypia increased, and the ascent of atypical melanocytes and pagetoid spread became conspicuous. Mitoses became apparent only from the progressive stage. From these observations, we would like to propose three new pathological clues of early stage subungual melanoma: (i) "skip lesion", proliferation of the tumor cells are more prominent in the hyponychium than in the nail bed or nail matrix; (ii) histological confirmation of Hutchinson's sign; and (iii) epithelial thickening and/or compact arrangement of the elongated basal cells. [source] Atypical moles in a patient undergoing chemotherapy with oral 5-fluorouracil prodrugBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2004S. Fukushima Summary We present a patient with multiple pigmented lesions on the palms, soles, oral mucosa and nails after chemotherapy with oral 5-fluorouracil (5-FU) prodrug. Dermoscopically, most of the macules showed similar features, with pigmentation present predominantly on the crista superficialis, while a large, dark macule also showed pigmentation along the sulcus superficialis with irregular hyperpigmentation and depigmentation, suggesting malignancy. However, histologically, both types of lesion showed basal hyperpigmentation and the presence of a small number of large atypical melanocytes. We diagnosed these lesions as pigment flecks induced by 5-FU, and the pigmented lesions gradually diminished after the cessation of chemotherapy. Our findings suggested that immunosuppression and 5-FU led to the development of the atypical pigmented lesions. [source] | ||||||||||