Paraganglioma-like Dermal Melanocytic Tumor

Abstract

We are reporting a previously undescribed primary dermal melanocytic tumor identified by reviewing all dermal melanocytic tumors referred in consultation that did not qualify histologically as a previously described entity. From these cases, 8 were remarkably similar. We termed them "paraganglioma-like dermal melanocytic tumor" (PDMT) based on their nested growth pattern. This term is used descriptively and does not imply any histogenetic or biologic similarity to true paraganglioma. PDMT is primarily a tumor of the extremities of adult females (18-53 years, mean 35 years; males 2; females 6) which present as a dermal nodule (range, 0.5-4.2 cm; mean, 1.4 cm) composed of nests of clear to amphophilic oval cells separated by delicate fibrous strands. Nuclear atypia was mild and mitotic activity low (1-4 mitoses/10 HPF). Melanin was not obvious on light microscopy. Tumors expressed S-100 protein (8 of 8), Melan-A (4 of 8), HMB-45 (8 of 8), and microphthalmia transcription factor (8 of 8) and lacked pancytokeratin (8 of 8) and smooth muscle actin (8 of 8). FISH analysis of 5 cases revealed an intact EWS gene locus, supporting absence of the clear cell sarcoma 12;22 translocation. Follow-up information in 8 patients (range, 35-92 months; mean, 54 months) indicated that all were alive without disease. PDMT comprises a clinically and pathologically unique subtype of dermal melanocytic tumors. Our study suggests a benign course, although a lesion of low malignant potential cannot be excluded.

The Great Mime: Three Cases of Melanoma with Carcinoid-Like and Paraganglioma-Like Pattern with Emphasis on Differential Diagnosis

“…Here, we present three cases of very rare variants of melanoma, in which the neoplastic cells were distributed in carcinoid and paraganglioma patterns. Clinically, these lesions are heterogeneous and can affect patients of all ages, with disparate clinical pictures such as papules (skin tag-like) by Sarma et al [8] or nodular non-pigmented and painless lesions, as reported by Cimpean et al [9]. However, no clinical pattern can be reliable in discriminating a PDMT from a melanoma with carcinoid and paraganglioma-like features.…”

Paraganglioma-like dermal melanocytic tumor

“…in 2004. [ 1 ] There are only 10 PDMT cases reported in literature and 8 of them were retrospectively diagnosed in the study by Deyrup et al . while reviewing all dermal melanocytic tumors that did not qualify histologically as a previously described entity.…”

“…Tumors express S-100, melan A, HMB 45 and lack pancytokeratin markers. [ 1 4 ] There is no necrosis but increased mitotic activity can be rarely encountered. [ 2 ] These histopathologic features are reminiscent of those of paraganglioma but tumor cells of paraganglioma are usually negative for melanocytic markers.…”

“…The term was based on their nested growth pattern in histology, which shows nests of clear to amphophilic oval cells separated by delicate fibrous strands. [ 1 2 ] Only 10 cases have been reported so far and to the best of our knowledge none in dermatology journals.…”

Clear cell sarcoma: A case mimicking primary cutaneous malignant melanoma

“…Their common embryologic origin, similar histologic, and immunohistochemical features make differential diagnosis difficult. [3–616–18]…”