MALIGNANT MESOTHELIOMA METASTATIC TO THE SKIN, PRESENTING AS INFLAMMATORY CARCINOMA

We report a 50-year-old man with a history of malignant pleural mesoth elioma diagnosed 1 year previously and treated with pneumonectomy and radiotherapy who presented with an erythematous eruption on the left c hest wall. A skin biopsy showed a proliferation of malignant epithelio id cells lining irregular clefts in the dermis. Some groups of cells w ere observed filling vascular lumina. Immunohistochemically, the tumor cells expressed cytokeratins (with antibodies AE1/AE3, MNF 116, and C AM 5.2), and epithelial membrane antigen (EMA), and were negative with Ulex europaeus (UE) and for carcinoembryonic antigen (CEA), CD34, CD1 5 (with LeuM1 antibody), and factor VIII-related antigen (FVIIIra). Th e histologic features and immunohistochemical profile were comparable to those observed in the primary pleural mesothelioma. This is the fir st reported case in which malignant mesothelioma metastatic to the ski n presented as ''inflammatory carcinoma.'' Although a very uncommon pr esentation, mesothelioma should be considered in the differential diag nosis of erythematous eruptions on the chest.