Clear Cell Mesothelioma

A clear cell form of epithelial mesothelioma is described. This variant does not appear to have been previously described, and it merits recognition since it is readily confused by routine light microscopy with other tumors that involve the pleura, including metastatic carcinomas composed predominantly of cells with optically clear cytoplasm. Ultrastructural and immunohistochemical studies were helpful in reaching the diagnosis in this case, and electron microscopy is particularly recommended to investigate the differential diagnosis of unusual pleural tumors.