Fetus-in-fetu presenting as acute intestinal obstruction

Fetus-in-fetu is a rare condition in which a fetiform calcified mass is often present in the abdomen of its host; a newborn or infant. We present the case of a three-month-old male baby with acute intestinal obstruction and abdominal mass. X-ray abdomen and ultrasonogram revealed a cystic mass with calcification. On laparotomy, a well encapsulated retroperitoneal mass causing high intestinal obstruction was identified. Total excision of the mass was done. Diagnosis of fetus-in-fetu was confirmed on histopathology. Postoperative recovery was uneventful.