Concomitant Wilms tumor and autosomal dominant polycystic kidney disease

Abstract Background Concomitant Wilms tumor (WT) and autosomal dominant polycystic kidney disease (ADPKD) is exceedingly rare, presenting a diagnostic and technical challenge to pediatric surgical oncologists. The simultaneous workup and management of these disease processes are incompletely described. Procedure We performed a retrospective analysis of patients treated at our institution with concomitant diagnoses of WT and ADPKD. We also review the literature on the underlying biology and management principles of these conditions. Results We present three diverse cases of concomitant unilateral WT and ADPKD who underwent nephrectomy. One patient had preoperative imaging consistent with ADPKD with confirmatory testing postoperatively, one was found to have contralateral renal cysts intraoperatively with confirmatory imaging post nephrectomy, and one was diagnosed in childhood post nephrectomy. All patients are alive at last follow‐up, and the patient with longest follow‐up has progressed to end‐stage kidney failure requiring transplantation and dialysis in adulthood. All patients underwent germline testing and were found to have no cancer predisposition syndrome or pathogenic or likely pathogenic variants for WT. Conclusion Concomitant inheritance of ADPKD and development of WT are extremely rare, and manifestations of ADPKD may not present until late childhood or adulthood. ADPKD is not a known predisposing condition for WT. When ADPKD diagnosis is made by family history, imaging, and/or genetic testing before WT diagnosis and treatment, the need for extensive preoperative characterization of cystic kidney lesions in children and increased risk of post‐nephrectomy kidney failure warrant further discussion of surgical approach and perioperative management strategies.