A well-documented multimodality imaging approach to fetus in fetu: pre- and postnatal imaging features

Abstract

Fetus in fetu (FIF) is a very rare congenital condition with an incidence of 1/500,000 live births [1]. It resembles a mature teratoma, but also contains a vertebral column and shows a variable degree of organogenesis [2]. The abnormality has the features of a monozygotic diamniotic, parasitic twin, is attached by vascular anastomoses to its host twin’s chorionic circulation and is typically incorporated into the body of its host twin [3]. We report a new case of fetus in fetu that presented prenatally as a cystic abdominal lesion with heterogeneous appearance on both US and magnetic resonance imaging MRI. Postnatally, we successfully clarified the diagnosis on imaging [radiography, US, MRI and computed tomography (CT)]. The diagnosis was confirmed histopathologically. Case report