Unusual Presentation: Nephroblastoma/Wilms tumor in an Adult – A Case Report

Abstract Introduction/Objective Nephroblastoma/Wilms tumor is a common renal tumor primarily observed in children, and its occurrence in adults is exceedingly rare. This rarity contributes to the diagnostic challenges encountered in adults. Here, we present a case of a 32-year-old male diagnosed with biphasic nephroblastoma/Wilms tumor in the kidney, with liver and lung metastases. Methods/Case Report A 32-year-old male, without significant past medical history, presented with the chief complaint of abdominal pain for 2-3 weeks. Imaging studies revealed a substantial 17.5 cm kidney lesion accompanied by numerous lung and liver lesions. A liver biopsy indicated a small blue cell tumor, morphologically and immunophenotypically, (positive WT1) resembling nephroblastoma, with a strong suspicion of metastasis. Subsequent kidney biopsy confirmed a small blue cell malignant tumor demonstrating biphasic features, including blastema and epithelial components forming tubular structures similar to the liver biopsy, predominantly showing the blastemal component. The renal tumor biopsy supported the diagnosis of nephroblastoma. Despite chemotherapy, the patient passed away two months after the initial liver tumor biopsy. Results (if a Case Study enter NA) NA Conclusion Diagnosing nephroblastoma in adults poses significant challenges, particularly when initial presentations involve metastases. The occurrence of pediatric tumors in adulthood, though rare, should be considered in the diagnostic process after exhausting other possibilities. It is also important to note that the clinical presentation of pediatric tumors in adults may deviate from typical patterns. While Wilm’s tumor commonly presents as a painless, palpable abdominal mass in pediatric cases, adults may exhibit abdominal pain as the predominant symptom, as present in our case.