Twin fetus in fetu-a very rare entity: a case report with review of literature

1] To report a very rare condition of conjoined twining in fetus in fetu in an infant. From literature it appears to be the 4th case being reported. 2] To emphasize the importance of proper examination of the fetus in fetu grossly by doing extensive dissection, radiologically and detailed histological tissue examination from several sites. Design: Detailed report of an unusual intra-abdominal mass in an infant. Setting: Department of Pediatric Surgery, Children Hospital, PIMS, Islamabad. Successfully treated with surgical removal and interesting diagnosis emerged. Twin fetus in fetu [FIF] is a very rare anomaly due to an abnormal embryogenesis of fetus during pregnancy. Malformed fetus grows in the body of co-twin and it is frequently detected as an abdominal mass. There is no clear distinction between the term of FIF and fetiform teratoma [FT]. We are reporting a case in which a girl was referred as a case of nephroblastoma but at operation and on detailed examination of the specimen it turned out to be a case of twin fetus in fetu