Imaging of Fetal Tumors

Fetal tumors have appearances in utero that differ from those seen in neonates and children. Knowledge of these differences is important when assessing a potential fetal neoplasm. Tumors are typically found during routine obstetric ultrasound or in a patient large for dates, either because of the size of the tumor or associated polyhydramnios. After diagnosis, ultrasound is used to follow fetal growth, tumor growth, and any associated abnormalities. Doppler examination is important for differential diagnosis of masses and prediction of outcome. Magnetic resonance imaging frequently adds additional information regarding tissue characterization and organ involvement. The purpose of this review is to describe and illustrate the appearance of fetal tumors with suggestions for differential diagnosis when a fetal mass is visualized.