Fetus in fetu in the scrotal sac of newborn

Fetus in fetu (FIF) in the scrotal sac is often overlooked in the differential diagnosis of other scrotal swellings in infants and children. Unlike  teratoma, FIF is a benign disorder. Scrotal FIF is extraordinarily rare and has been reported only twice in the international literature. We describe the case of a 15-day-old neonate who presented with scrotal swelling since birth. Radiography and ultrasound revealed a FIF. On surgical removal and pathological evaluation, the anencephalic fetus had limb buds, male external genitals, and vertebral column, supporting the diagnosis of FIF. FIF in the scrotum is a very rare entity. It should be  differentiated from other scrotal swellings such as teratoma because of the malignant potential of the latter. Preoperative diagnosis is based on radiologic findings. The treatment is complete excision.Keywords: fetus in fetu, pluripotent cells, scrotal swelling, scrotal teratom