Malignant mesotheliomas in spermatic cords: reports of two cases and a brief review of literature.

Primary malignant mesothelioma (MM) of spermatic cord is extremely rare. We presented two malignant mesotheliomas involving the spermatic cords; one was primary, one secondary. The secondary one represented the direct involvement by a peritoneal MM. No occupational exposure to asbestos was identified in either patient. Both of them presented with a painless inguinal mass. Microscopically the primary MM was epithelioid type with tumor nests infiltrating adjacent adipose tissue, while the secondary MM grew in mixed type. No tumor necrosis was seen in the primary MM, while extensive necrosis was seen in the secondary one. Rare mitotic figure was seen in the primary MM while the mitosis in the secondary tumor was brisk, and with atypical mitosis. Immunohistochemically the tumor cells were positive for calretinin and CK5/6 and negative for BER-EP4 and BRST3 in both cases. The reported cases of primary MM from spermatic cord in English literature were briefly reviewed.