Malignant mesothelioma: Cytological features

A malignant mesothelioma arises from the serosal surface of the pleural, peritoneal, or pericardial cavity. Although rare, with development of diagnostic techniques, the frequency of this tumor has been increasing. Malignant mesothelioma is classified into three types; epithelioid, sarcomatoid, and biphasic. It is especially important to differentiate epithelioid type from reactive mesothelial cells and another type of carcinoma, with a definitive diagnosis usually obtained based on examination of tissue biopsy or surgical resection specimens.