RESUMO
Well Differentiated Papillary Mesothelioma (MPBD) is a very rare neoplasm that mainly affects women of reproductive age. The most common location is the peritoneum and it is an incidental finding, with a generally favorable prognosis. We present three cases diagnosed incidentally, in the course of a surgical intervention of various causes, which presented as peritoneal exophytic lesions not detected in the pre-surgical imaging study. It is important to keep this entity in mind, to differentiate it from other neoplasms with an unfavorable prognosis and evolution, such as Malignant Mesothelioma or primary and metastatic carcinomas. Recent studies give the MPBD a specific immunohistochemical and molecular profile that allow a greater diagnostic precision of the entity.