Amelanotic Malignant Melanoma with Dense Pleural Thickening Mimicking Malignant Mesothelioma.
A 51-year-old man was diagnosed with stage IIC nodular malignant melanoma (T4bN0M0) of the right upper arm. The tumor was treatment-refractory, and left-sided pleural effusion emerged 1.5 years later. Aspiration of pleural fluid revealed abundant amelanotic, atypical cells that resembled epithelial malignant mesothelioma or lung adenocarcinoma cells; these cells were positive for melanoma-associated antigen recognized by T cells (MART-1)/Melan-A, HMB-45, and S-100 on immunocytochemistry. Thoracic computed tomography (CT) revealed marked diffuse pleural thickening in the left hemithorax that mimicked malignant mesothelioma; thus, the present report describes the unique cytological and radiological findings of this case.
['Saraya|Takeshi|T|', 'Fujiwara|Masachika|M|', 'Morita|Kikuko|K|', 'Watanabe|Takayasu|T|', 'Ogawa|Yukari|Y|', 'Takizawa|Hajime|H|', 'Light|Richard W|RW|']
D001706:Biopsy D003937:Diagnosis, Differential D006801:Humans D008175:Lung Neoplasms D008297:Male D018328:Melanoma, Amelanotic D008654:Mesothelioma D000086002:Mesothelioma, Malignant D008875:Middle Aged D010994:Pleura D010997:Pleural Neoplasms D014057:Tomography, X-Ray Computed
malignant melanoma pleural effusion amelanotic melanoma nodular type