Two Cases of a Rare Congenital Anomaly: Fetus in Fetu

Abstract

Fetus in fetu is a rare anomaly seen in 1 in 500,000 births. It presents as a retroperitoneal mass which may remain unnoticed till later age. We present two interesting cases of fetus in fetu (FIF), its diagnosis, treatment, and histological findings. The first case was ten-month-old male baby who presented with symptoms and was diagnosed pre-operatively as FIF, later confirmed by postoperative radiograph and histology. The second case was six-month-old female child diagnosed as having a mass suggestive of teratoma in retroperitoneum and the diagnosis of FIF was made intra and postoperatively. We conclude that FIF is a benign retroperitoneal mass having varied presentation and may be confused with teratoma. Advances in diagnostic modalities have made it possible to diagnose this condition prenatally. Surgical excision is curative with good outcome. Histology can confirm the diagnosis as it is important to differentiate FIF from teratoma which has malignant potential. KEYWORDS: Fetus In Fetu, Teratoma, Congenital Anomaly, Retroperitoneal Mass, Histology.