Fetus in Fetu: A Case of Vanishing Triplet Phenomena

Fetus in fetu (FIF) is a rare congenital disorder in which a deformed fetus forms inside a normal one, mostly within the abdominal cavity. In this case study, we present a triplet pregnancy where one fetus was formed within a viable fetus. This was noted in prenatal imaging and upon delivery. Radiological investigations were conducted, including plain X-rays, abdominal computed tomography, and magnetic resonance imaging, and a preliminary case of FIF was diagnosed. Following this, surgical resection was planned and done soon after birth with histopathology confirmation of diagnosis, and it revealed no evidence of somatic malignancy. Currently, the patient is in stable condition and is being followed up with serial ultrasound imaging with alpha-fetoprotein levels to detect recurrence.