Sarcomatoid type of paratesticular malignant mesothelioma in a dry-cleaning worker exposed to asbestos and diagnostic value of WT-1

Of the 3 major histologic types of malignant paratesticular mesothelioma (MPM) (epithelial, sarcomatoid, and biphasic), many cases of epithelial and biphasic mesothelioma have been reported in the literature. Pure sarcomatoid MPM is the least common but the most aggressive of the 3 major histologic types of mesothelioma cells. It is limited to only 2 cases in the literature The sarcomatoid type of MPM can be confused clinically and histologically with true sarcomas because it is rarely seen. We present a case who had been exposed to asbestos for years due to his involvement in the dry-cleaning industry and who was diagnosed with the sarcomatoid type of MPM but had a relatively prolonged survival not usually seen with this tumor. This report also emphasizes the significance of an immunohistochemical examination, focusing especially on the diagnostic role of WT-1. © 2020, University of Puerto Rico. All rights reserved