Imaging Characteristics of Pediatric Renal Cell Carcinoma and Wilms Tumor and Its Impact on Their Managementand Outcomes

Renal cell carcinoma (RCC) in children is rare, comprising only 1.4–6.3% of pediatric renal tumors. Differentiating RCC from Wilms tumor, the most common pediatric renal tumor is crucial due to differing management and prognosis. Imaging characteristics, such as the presence of calcifications and cystic components, guided the decision to perform surgery without pretreatment biopsy, reducing the risk of needle tract seeding. Translocation-associated RCC is the most common subtype in children, and surgical resection remains the cornerstone of treatment. Long-term follow-up is essential due to the potential for late recurrences. We are reporting the details of a 4-year-old boy, who presented with a 15-day history of fever and abdominal distension, accompanied by a ballotable mass in the right lumbar region. Imaging studies, including a CT scan, revealed a large complex cystic mass in the right kidney, consistent with Bosniak category IV, and enlarged paraaortic nodes. Further evaluation with an FDG-PET scan confirmed the uptake only in the right kidney. The child underwent a right radical nephrectomy with retroperitoneal lymph node dissection. Histopathology revealed translocation-associated RCC features, characterized by slender papillae, psammoma bodies, necrosis, and uniform epithelial cells with hyperchromatic nuclei. Immunohistochemistry showed positivity for markers including TEF3, keratin, and vimentin, with a KI-67 proliferation index of 10–20%. The final stage was pT2aN0, and the patient had an uneventful recovery, with no recurrence at 36 months of follow-up.