[Malignant mesothelioma of the tunica vaginalis testis].

A 74-year-old man underwent hydrocelectomy following repeated fluid aspiration, six times during the previous year. Tunica vaginalis was opened after removing about 70 ml of yellow clear fluid and many miliary sized soft papillary tumors were seen inside of the vaginal sac. These tumors were attached to the sac so closely that they were easily rubbed off with a towel. The pathological specimen showed a papillary structure combined with solid sheets of cells. The cells were cuboidal and polygonal with sparse mitotic figures and the nuclei were round or oval with prominent nucleoli. Malignancy was strongly suspected and orchiectomy was performed a month later. Pathologic examination of the operated material showed that the tumor cells invaded into the tunica albuginea, and the diagnosis of malignant mesothelioma was finally made. The patient has remained well with neither recurrence nor metastasis for fifteen months.