Bilateral Wilms tumor with neonatal onset and the importance of prenatal diagnosis

Wilms tumor (WT) occurs in 1:10.000 live births and affects mainly the unilateral kidney. The National Wilms Tumor Study Group registered 6832 patients with WT from 1969 to January 1993, out of whom only 11 patients (0.16%) were newborns. Since 1969, 14 cases of prenatal diagnosis of WT have been reported in literature, two of which were bilateral WT. Currently, the patients' survival rate is greater than 90%, owing to a combination of surgery, chemotherapy, and radiotherapy for high-risk patients. We report a case of bilateral WT, undiagnosed during the prenatal period due to the incomplete evaluation of the abdomen with ultrasonography. The newborn was vaginally delivered at 40 weeks' gestational age with a good perinatal adaptation. Suddenly, during the night the newborn showed respiratory distress, bradycardia and then respiratory arrest. For this reason, he was ventilated, intubated and subjected to conventional mechanical ventilation. Despite the normal cardiac ultrasonography, the health care providers suspected a cyanotic congenital heart disease with duct dependency. After a gradual resumption of the oximetry and blood pressure, the infant was transported by the neonatal emergency transport system to the Cardiac Pediatric Surgery Department of a level III hospital. There, the clinical condition became extremely serious and the infant died of asystole. During autopsy, two large tumoral masses were found in both kidneys, also the characterization of the tumors was done through histological exam, which confirmed the diagnosis of WT. A prenatal diagnosis of WT is very important because the families can take advantage of prenatal counseling to understand the risks of continuing the pregnancy and to evaluate the need for abortion, while health care providers can prepare to face a difficult delivery. The review of the literature suggests that prenatal diagnosis of bilateral WT is possible. During prenatal age, the complete assessment of the abdomen with ultrasonography and Eco-Color-Doppler can reveal kidney anomalies and raise suspicion of diseases with urinary malformations