Fetus-in-fetu in an 8-month-old girl

Abstract

Fetus in fetu (FIF) is a very rare congenital malformation with an incidence of 1/500,000 live births. These children are often hospitalized because of vomiting, abdominal distension or abdominal mass found by their parents. The most common position for the parasitic fetus is the retroperitoneum but other position such as the scrotal sac, cranial cavity, sacrococcygeal region, back , oral cavity has been reported. FIF is often misdiagnosed as a mature teratoma. Ultrasound, CT, MRI are of great significance in distinguishing between FIF and teratoma. The postoperative pathological examination may reveal axial skeleton which can make a definitive diagnosis of FIF. In this report, we present a case of FIF in an 8-month-old girl.