Synchronous Pleural and Peritoneal Mesothelioma in a Free-Ranging Capuchin Monkey (Sapajus libidinosus).

A free-ranging capuchin monkey developed a synchronous biphasic pleural and peritoneal mesothelioma, a rare form of this tumor. Exophytic nodules were dispersed over the serosal surfaces, showing marked microscopical malignant features composed of both epithelioid and spindeloid neoplastic cells immunopositive for Pan-Cytokeratin, Cytokeratin 5/6, Vimentin, WT-1, and D2-40.