Well-Differentiated Papillary Mesothelioma of the Peritoneum: Report of a case

ABSTRACT

We described a case of well differentiated papillary mesothelioma (WDPM) of the peritoneum in a 68-year-old man because of its rarity. It was incidentally found during operation for renal cell carcinoma. Grossly, the tumor appeared as multiple small granules or nodules on the entire peritoneal surface, including serosa of the intestine, omentum and mesentery. Microscopically, characteristic features are papillary, tubulopapillary or solid architecture lined by single layer of uniform, cytologically bland, cuboidal or polygonal mesothelial cells. The tumor cells were positive for EMA, cytokeratin and vimentin, but negative for CEA on immunohistochemical staining. Ultrastructural study showed characteristic long slender microvilli on the surface and intercellular junctions.