Prenatal sonographic features of a rhabdoid tumor of the kidney.

Rhabdoid tumors of the kidney are highly lethal malignancies of infancy. We report the prenatal detection of a renal rhabdoid tumor with mesoblastic components in a fetus at 27 weeks of gestation. The tumor presented as a large mass in the left renal area and there was concomitant massive polyhydramnios. Though the sonographic features alone did not allow distinction from a benign lesion, the aggressive tumor growth indicated malignancy. Amniotic fluid cytology was performed but failed to confirm the diagnosis. Corticosteroids were administered for lung maturation. Tocolysis, including betamimetics, magnesium and indomethacin, was performed to prevent premature labor. Additionally, serial amniodrainage was performed. At 30 weeks of gestation fetal hydrops developed and a Cesarean section was performed. After delivery, ventilation of the preterm infant was insufficient due to diaphragm elevation by the huge tumor, requiring immediate tumor surgery. However, though ventilation was improved the infant died of cardiac failure 4 h after surgery.