Purpose or Case Report: To present an extremely rare case of fetus in fetu which was discovered with prenatal ultrasound and fetal MR.
Methods & Materials: Prenatal ultrasound and fetal MR images were correlated with post-natal CT, ultrasound, and radiographs for a multimodality evaluation of the patient with both prenatal and postnatal imaging.
Results: Fetus in fetu is an exceedingly rare diagnosis. This case provides both prenatal and postnatal imaging of the patient and the fetus in fetu found to be occupying the patient's right ovary. Differentiation of this diagnosis from teratoma is important as there is less risk for malignancy in fetus in fetu. Identification of organization of osseous and soft tissue elements is essential for differentiating this diagnosis from teratoma.
Conclusions: An extremely rare case of fetus in fetu is presented, which was found prenatally. Multimodality evaluation of the abnormality was performed both prenatally and postnatally allowing for comparison of the findings with prenatal ultrasound, fetal MR, postnatal radiographs, postnatal ultrasound, and postnatal CT examination.