Fetus in fetu: A rare case report

Background: fetus in fetu is a rare congenital anomaly in which malformed fetus grows within the body of its twin. it is almost al- ways detected as an abdominal mass in infancy. it is a parasitic twin of a diamniotic, monozygotic twin. it should be differentiated from teratoma which has no axial arrangement and has got definite malignant potential. herein, we present a case of a two-month old female infant and review the literature. although fetus in fetu is a rare condition, correct diagnosis using imaging can be made before surgery. it should be considered as a differential diagnosis for lump abdomen especially in infants. complete excision is curative.