Macroscopic, histologic, histochemical, immunohistochemical, and ultrastructural features of mesothelioma.

Mesotheliomas are uncommon neoplasms that arise from the cells forming the serosal membranes of the body cavities. Approximately 90-95% of mesotheliomas arise in the pleural cavity and 5-10% in the peritoneal cavity. Rare mesotheliomas arise in the pericardium and in the tunica vaginalis. Unlike many neoplasms, mesotheliomas grow in a diffuse distribution and tend to encase the organs in the various body cavities. A combination of histochemical, immunohistochemical, and ultrastructural features are often necessary to accurately diagnose mesotheliomas. These techniques are highlighted in this review article on mesothelioma.