Sacral Parasite Conjoined Twin Mimicking Sacrococcygeal Teratoma: Multi Detector CT Findings

Sacral parasite conjoined twins are rare form of conjoined twins. Differential diagnosis of the parasitic twin includes fetus in fetu (internal parasite) and teratoma. A 2900 g boy was born by normal vaginal delivery to a healthy young mother. At birth, the infant was found to have a large mass, attached to his sacrococcygeal region. Radiologic and histopathological examinations showed long and short bones within the sacral parasite. We present a rare case of parasitic conjoined twin attached to the sacrococcygeal region of the autosite who were evaluated by multidetector computed tomography including 3D volume rendering images.