Well-differentiated papillary mesothelioma

Well-differentiated papillary mesothelioma is an unusual variant of epithel ial mesothelioma considered to be of low malignant potential. The majority of previously reported cases developed in the peritoneum of young women wit hout a history of asbestos exposure. The authors report 14 cases of well-di fferentiated papillary mesothelioma, seven of which originated in the pleur a, six in the peritoneum, and one in the tunica vaginalis. Eleven of the pa tients were male and three were female, with an average age at presentation of 58 years (range 32-82 years). Six of the patients had a quantifiable hi story of asbestos exposure. Of the nine cases with complete follow-up, six had clinically indolent disease, one showed resolution after adjuvant chemo therapy, one pursued an aggressive course, and one died of other causes. Th ese findings indicate that well-differentiated papillary mesothelioma is a rare variant of mesothelioma with a variable clinical prognosis that is eti ologically related to asbestos exposure in some cases.