Congenital mesoblastic nephroma and polyhydramnios.

Polyhydramnios and premature delivery complicated the pregnancies of three women whose infants were born with renal tumors. In each case the tumor was a mesoblastic nephroma. The liquid of polyhydramnios enhances detection of masses in the fetal abdomen by ultrasound. In the future, mesoblastic nephroma may, therefore, be diagnosed antenatally. Tumors in these infants, which have proved in most cases to be benign, are usually cured by surgical removal. Occasionally, local infiltration and adhesions prevent removal. The fate of the infant with residual tumor is not known.