Sparganosis in male breast.

Humans can acquire infection by sparganum or plerocercoid larva of the tapeworm from drinking water containing infected Cyclops species and by ingesting infected snakes, birds, or other mammals. Once infected, the plerocercoid larva migrate slowly in the tissues and present as a subcutaneous lesion, making the correct diagnosis difficult. A 38-year-old man visited our clinic due to a breast mass. Due to suspicion of gynecomastia or breast cancer, he underwent tumor excision. Unexpectedly, a long white worm was found in the breast tissue and the pathologic finding showed sparganosis. After the surgery, mebendazole was prescribed for 1 week. No recurrence of the sparganosis was found during 1-year follow-up.