ULTRASONIC AND MAGNETIC-RESONANCE-IMAGING OF FETAL SACROCOCCYGEAL TERATOMA

Objective. To evaluate ultrasonic and magnetic resonance imaging (MRI) and Doppler examination in fetal sacrococcygeal teratoma (SCT), in re spect to the postnatal findings and histological type of the rumor. St udy design. Nine pregnancies complicated by histologically mature feta l sacrococcygeal teratoma in four cases and by immature/ malignant ter atoma in five cases. Transabdominal ultrasonic imaging and Doppler vel ocity waveforms were recorded during the second or last trimester in a ll cases, first trimester ultrasound examination was carried out in si x cases and last trimester MRI in five cases. These findings were comp ared with postnatal and operative findings of the children. Results. U ltrasound examination did not reveal intrapelvic parts of SCT, but thi s was possible by MRI. Velocity waveforms of the tumor arteries were s imilar in all histological types and the resistance index varied from 60 to 70. The mean gestational age at antepartal diagnosis was 25.2 we eks. Large tumor size with relatively large proportion of solid compon ents was often recognized in cases with malignant/immature histology. Conclusions. Antepartal MRI is useful for examination of fetal SCT, bu t reliable differentiation of mature and immature SCT is not possible antepartally.