1980 Volume 71 Issue 8 Pages 961-968
The benign renal tumor of the newborn has received increasing attention in recent years. In the past, it was generally confused with nephroblastoma. The degree of differentiation and the obvious lack of malignant features of this tumor distinguish it from the usual malignant nephroblastoma. Recently, the term “Congenital Mesoblastic Nephroma” has been adopted to describe this tumor. In this paper, two cases of congenital mesoblastic nephromas were studied.
Case 1: A 4-day-old female was admitted for investigation of a left flank mass. There were no urinary symptoms. The child, born 6 weeks prematurely, weighed 2240g at birth. The mother had polyhydramnios for several weeks prior to delivery. The left kidney was resected on August 11, 1976. The specimen measured 6.5×5.5×3.7cm and weighed 69g. The cut surface of the tumor had a yellowish-gray color and watered-silk appearance. There was no hemorrhage or necrosis. Microscopically, tumor was composed of compact interlacing bundles of elongated spindle cells. There was immature cartilage and clustering of vascular channels in tumor. No radiation or chemotherapy was given.
Case 2: A 2800g girl was referred at 2 days of age when a right-sided abdominal tumor was found. The mother had polyhydramnios during the pregnancy but delivery was normal. Right nephrectomy was performed on February 7, 1978. The kidney and renal tumor together measured 10×15×10cm and weighed 170g. The surface of it was smooth and on cut section the mass had a white-yellow color. The histologic and cytologic features were similar to those in case 1. No other therapy was given.
Two patients were well and had no sign of reccurrence of tumor.
