부산대학교 도서관

Benign solid and acinar mesothelioma (BSAM)/adenomatoid tumor of the testis most frequently occurs in adulthood, being derived from the testicular tunics or adnexal structures. The tissue of origin for this tumor has been debated, although recent evidence, based upon ultrastructural and immunohistochemical findings, is indicative of its being a benign form of mesothelioma. BSAM has a variety of morphologic patterns, ranging from cords and sheets of cells (solid type) to acinar and cystic structures (acinar type), although one type usually predominates.The case presented is a 31-year-old male who noted an enlarging testicular mass. At operation a tumor was found adjacent to the lower pole of the epididymis, and on histologic examination, this was shown to be a solid-type BSAM. The variable morphology of BSAM predicates an extensive differentiated diagnosis, which includes benign and malignant tumors of stromal and epithelial origin. The lesion most likely to be confused with BSAM is histiocytoid (epithelioid) hemangioma, and immunohistochemistry, utilizing vascular markers, is necessary to facilitate a diagnosis. Other lesions in the differential diagnosis are yolk sac tumor, sclerosing seminoma, sclerosing Sertoli cell tumor, large cell calcifying Sertoli cell tumor, carcinoid, rete adenoma/adenocarcinoma, epididymal papillary cystadenoma/adenocarcinoma, malignant mesothelioma, metastatic carcinoma, and sclerosing lipogranuloma.