Malignant mesothelioma metastatic to the skin, presenting as inflammatory carcinoma

We report a 50-year-old man with a history of malignant pleural mesothelioma diagnosed 1 year previously and treated with pneumonectomy and radiotherapy who presented with an erythematous eruption on the left chest wall. A skin biopsy showed a proliferation of malignant epithelioid cells lining irregular clefts in the dermis. Some groups of cells were observed filling vascular lumina. Immunohistochemically, the tumor cells expressed cytokeratins (with antibodies AE1/AE3, MNF 116, and CAM 5.2), and epithelial membrane antigen (EMA), and were negative with Ulex europaeus (UE) and for carcinoembryonic antigen (CEA), CD34, CD15 (with LeuM1 antibody), and factor VIII-related antigen (FVIIIra). The histologic features and immunohistochemical profile were comparable to those observed in the primary pleural mesothelioma. This is the first reported case in which malignant mesothelioma metastatic to the skin presented as "inflammatory carcinoma." Although a very uncommon presentation, mesothelioma should be considered in the differential diagnosis of erythematous eruptions on the chest.