[Malignant mesothelioma of the tunica vaginalis: a case report].

: An 18-year-old man visited our hospital with a painless swelling of the left scrotal contents. Transscrotal ultrasonography revealed a hydrocele and a 10-mm nodular mass attached to the tunica vaginalis. Tumor resection and hydrocelectomy were performed because the intra-operative histological diagnosis of a frozen section did not reveal malignancy. However, since the postoperative pathological diagnosis was malignant mesothelioma, the left hemiscrotum was excised. He has been free of disease 15 months postoperatively.