The outcome of prenatally diagnosed renal tumors
Leclair MD, El-Ghoneimi A, Audry G, Ravasse P, Moscovici J, Heloury Y; French Pediatric Urology
Study Group
Department of Pediatric Urology, Hopital Mere-Enfant, Centre Hospitalier Universitaire de Nantes,
Nantes, France
J Urol. 2005; 173: 186-9

• Purpose: We assessed the incidence of perinatal morbidity and evaluated the outcome in children with prenatally diagnosed renal tumors in a retrospective multicenter study.
• Materials and Methods: A review of the records of patients from 20 institutions identified 28 children with prenatally diagnosed renal tumors. Prenatal findings, clinical charts, and radiological, surgical and pathological reports were reviewed in this study.
• Results: There were 26 congenital mesoblastic nephromas and 2 Wilms tumors. One or more complications were identified in 20 of the 28 cases (71%) during the perinatal period. Polyhydramnios was observed in 11 fetuses (39%), 2 presented with hydrops fetalis and 7 presented in acute fetal distress requiring emergency cesarean section, of which 1 died in utero before delivery. Median gestational age of the 27 neonates born alive was 35 weeks (range 29 to 39), including 13 (46%) who were pre-term (less than 34 weeks of gestation). Complications at birth included hemodynamic instability in 3 newborns, of whom 2 underwent emergency surgery, respiratory distress syndrome in 8 (30%) and hypertension in 6 (22%). Surgical complications occurred in 7 patients (26%), including tumor rupture in 1 and intraoperative bleeding with postoperative death in 1. At a median follow-up of 42 months (range 2 to 105) 26 of the 27 children were in complete remission.
• Conclusions: Fetal renal tumors have an excellent oncological outcome but a high risk of perinatal complications. Prenatal diagnosis should allow planning the delivery at a pediatric tertiary care center to avoid a potentially life threatening condition in neonates in the first hours of life.
  
  
• Editorial Comment
  Although neonatal renal tumors are rare, the authors report the outcome of 28 cases diagnosed prenatally. These tumors are thought to be benign based on the limited post-natal experience. However, the authors note a strikingly high complication rate, especially prenatally. Forty-six percent were born premature and a large number had hemodynamic instability, hypertension or respiratory distress. There were 7 major surgical complications. Although 26 of the 28 are doing very well at a mean follow-up of 42 months, the authors emphasize that when diagnosed in fetal life, the course of these patients is anything but benign.

Dr. Barry A. Kogan
Chief and Professor of Urology and Pediatrics
Albany Medical College
Albany, New York, USA