To present the surgical approach to a multifocal Wilms tumor found on screening ultrasound in an asymptomatic 2-year-old female.

A 2-year-old female with hemihypertrophy underwent screening imaging every 3 months with renal ultrasound. A solitary, incidental renal mass was detected. Physical exam was unremarkable except for left leg hemihypertrophy. Laboratory workup was largely normal other than an elevated lactate dehydrogenase. Staging imaging revealed multiple masses on the right kidney and a normal left kidney. There were no distant metastases. The most likely diagnosis was Wilms tumor. After receiving chemotherapy for 6 weeks, imaging revealed an excellent response to chemotherapy and surgery was performed.

The patient underwent open partial nephrectomy of the 3 tumors on the right. Prior to beginning, cystoscopy and ureteral stent placement was performed as it was felt the collecting system would likely be entered during resection. The renal hilum was not clamped throughout this resection and manual parenchymal compression was used to minimize global ischemia. Retroperitoneal lymph node dissection was also performed. The patient recovered well and was discharged home 5 days after surgery. Her stent was removed at home without complications. Final pathology revealed nephrogenic rests with all 7 lymph nodes were negative for malignancy.

Management of multifocal, unilateral Wilms tumor with open partial nephrectomy after neoadjuvant chemotherapy is an important part of protocol management for patients with Wilms tumor with predisposition syndromes.