Pathological Diagnosis of Malignant Mesothelioma

ABSTRACT

Malignant mesothelioma is a primary tumor of the serosal membranes, occurring in the pleura, peritoneum, pericardium, tunica vaginalis, and other related anatomical sites. It is well known that malignant mesothelioma may be a difficult tumor to diagnose pathologically. For the reliable diagnosis of mesothelioma, the adequate representative tissue samples are essential for the routine histology, histochemistry, electron microscopy, and immunohistochemical test. The main differential diagnosis includes metastatic adenocarcinomas or metastatic sarcomas, and even benign mesothelial diseases. As a practical diagnostic method for differential diagnosis of malignant mesothelioma, the immunohistochemistry using a panel of antibodies (positive and negative markers) is considered as the most valuable and useful tool. The use of at least 2 mesothelial markers and 2 or more epithelial markers is recommended, and a diagnostic panel including calretinin, Wilms tumor product 1, cytokeratin 5/6, carcinoembryonic antigen (CEA), and thyroid transcription factor (TTF)-1 could be helpful.