Primary Malignant Rhabdoid Melanoma

Abstract

Melanoma with rhabdoid features is an uncommon variant of malignant melanoma. Here, we describe a rare case of primary rhabdoid malignant melanoma. A 54-year-old man presented with a black tumor measuring 3×4 cm on the right forearm. Histologic sections showed a tumor mass with rhabdoid features composed entirely of polygonal neoplastic cells with eccentric nuclei, prominent nucleoli, and large hyaline cytoplasmic inclusions. The tumor cells were immunoreactive with HMB-45, S100, Fontana-Masson silver and vimentin, and negative for smooth muscle actin, CD68, CD34, CD99, synaptophysin, desmin, and PAS. The differential diagnosis for this tumor included malignant peripheral nerve sheath tumor, malignant peripheral neuroectodermal tumor and rhabdomyosarcoma. The patient was treated with a wide excision and a local skin graft. The excised tumor was entirely composed of rhabdoid tumor cells. No recurrence or metastasis was evident 4 months after removal. This article is relevant to rare cases of primary malignant melanomas showing rhabdoid tumor cells over the entire excised lesion.

Primary amelanotic rhabdoid melanoma of the forehead

“…[5][6][7] So far, to the best of our knowledge, only seven cases showing primary malignant rhabdoid melanomas have been described. 3,5 Diagnosis of cases without conventional histopathological features of melanoma is extremely challenging, especially due to the absence of melanin pigment, focal and very weak positivity of S100 protein and negativity for HMB-45 and MelanA. 8 The immunoprofile of our case is rather similar to that of previously reported cases.…”

“…1 In 1992 the rhabdoid variant of melanoma was first described by Bittesini et al 2 It is considered an extremely rare variant of malignant melanoma, better observed in metastatic cases than in primary melanomas. 3 Histopathologically it is characterized by the presence of large sheets or nests of polygonal tumour cells with abundant cytoplasm containing eosinophilic inclusions and a peripherally located nucleus. 4 An 80-year-old man, without relevant past dermatological history, presented to us with multiple reddish rapidly growing nodules on his forehead.…”

“…2 CD8+ lymphoid proliferation has an indolent clinical course. 3 Unlike aggressive epidermotropic CD8+ T-cell lymphomas, chemotherapy is not required, making differentiation clinically relevant. 4 However, there are no defined histological features or immunohistochemical markers for distinguishing CD8+ lymphoid proliferation.…”

Primary Amelanotic Rhabdoid Melanoma: A Case Report with Review of the Literature

“…Rhabdoid melanoma was first described by Bittesini et al in 1992 [ 1 ]. Since then, over 40 cases of metastatic or recurrent rhabdoid melanoma have been reported, but only 7 cases of PRM appear in the literature [ 4 , 5 , 6 , 7 , 8 ]. Here we report the first Japanese case of PRM in English.…”

Renal Cell Carcinoma with Rhabdoid and Sarcomatoid Features Presented as a Metastatic Thigh Mass with an Unusual Immunohistochemical Profile

“…It may acquire spindle cell morphology, which is designated as sarcomatoid differentiation and it may acquire rhabdoid features, which is designated as rhabdoid differentiation 1 . Rhabdoid features was described in other malignancies including carcinomas, 2 melanoma, 3 and sarcomas. 4,5 Cohesive epithelioid cells with eccentric vesicular nuclei, prominent nucleoli and intracytoplasmic hyaline esinophilic globules are the main features of rhabdoid cells 6 .…”