Congenital mesoblastic nephroma: Case study

Congenital mesoblastic nephroma (CMN) is rare, accounting for 3-10% of pediatric renal tumors. It is the most common renal neoplasm in neonates and in infants under the age of 3 months. It can be detected antenatally especially with judicious use of ultrasonography. Polyhydramnios and premature labor are frequent associations. Differential diagnosis include Wilms' tumor, malignant rhabdoid tumor, clear cell sarcoma of the kidney (CCSK), neuroblastoma and ossifying renal tumor of infancy (ORTI). There are three histological subtypes; Classic, cellular and a mixed type. Diagnosis can be done through imaging; Ultrasound, CT scan and/or MRI. Histopathology findings are confirmatory. Treatment is often by a radical nephrectomy though the cellular type may require adjuvant chemotherapy because it is prone to become aggressive. We report a 3 day old female who was referred with a congenital abdominal mass with a background history of polyhydramnios antenatally and preterm delivery at 35 weeks. Imaging studies showed a right renal mass involving the mid and lower pole of the kidney. The neonate underwent a right radical nephrectomy and histopathology confirmed the mass as a classic sub-type of CMN.