Concomitant Wilms' tumor and renal cell carcinoma: Challenges in management and a case report

ABSTRACT Introduction and importance: The concomitant occurrence of Wilms' tumor (WT) and Renal cell (RCC) carcinoma represents a very rare urological entity. While the majority of Wilms' respond to chemotherapy, RCC is known as a prototype of chemotherapy and radiation-resistant malignancy. The coexistence of these two renal malignancies gives a unique diagnosis and therapy challenges due to resistance to neoadjuvant chemotherapy. Due to the rarity of concomitant occurrence of these two malignancies in the same kidney and challenges associated with management, we report such a rare case we experienced in our hospital. Case presentation: A seven-year-old boy who attended our hospital with a history of progressive abdominal distension over the past six months. The Computed tomography scan suggested WT with metastasis to the lungs and cervical lymph nodes. However, the tumor was resistant to neoadjuvant chemotherapy and radical nephrectomy was performed and histology results showed concomitant occurrence of WT and RCC. Clinical discussion: Concomitant occurrence of WT and RCC poses a challenge in treatment, as while Wilms' tumor is sensitive to chemotherapy, RCC is the prototype of tumors that are chemo-resistant. Therefore, whenever there is no response to neoadjuvant chemotherapy in patients suspected to have WT, a differential diagnosis of concomitant occurrence with RCC should be considered. Conclusion: A differential diagnosis of concomitant Wilms' tumor and Renal Cell carcinoma should be considered whenever a pediatric tumor presumed to be Wilms' tumor is resistant to standard neoadjuvant chemotherapy for Wilms' tumor. Highlights