[A case of Sparganosis mansoni with a painless mass in the inguinal region and the scrotum].

Sparganosis mansoni rarely occurs in the inguinal and perineal regions in Japan. A case of Sparganosis mansoni with a painless mass in the left inguinal region is presented. A 67-year-old male visited our hospital with a complaint of a painless mass in the left inguinal region in May, 1995, and another mass appeared in the scrotum two days after the first visit. Ultrasonography revealed a solid subcutaneous mass 2 cm in diameter. These masses were surgically excised by an inguinal approach and a parasite, 10 cm in length, was found in the mass. The parasite was diagnosed histologically as Sparganosis mansoni, which is a larva of the genus Diphyllobothrium.