Mucin-positive epithelial mesothelioma.

: Mucin-positive epithelial mesothelioma is a rare, frequently unrecognized entity that should not be misinterpreted as metastatic adenocarcinoma, as each is associated with differing treatment and prognosis. Presented herein is a case of an acidic and neutral mucin-positive papillary mesothelioma of the right pleura, with cytologic, histologic, histochemical, immunohistochemical, and ultrastructural evaluation.