Sporadic Pediatric Renal Epithelioid Angiomyolipoma Mimicking Wilms Tumor: A Case Report and Literature Review.

Background: Renal angiomyolipomas (AMLs) are benign renal tumors arising from perivascular epithelioid cells and are often associated with tuberous sclerosis complex. Renal epithelioid angiomyolipoma (EAML) is a rare variant of AML, characterized by the predominance of epithelioid cells with malignant potential. Although EAML is typically seen in adults, especially females, its occurrence in children is extremely rare and can be difficult to distinguish from other renal tumors. Case Presentation: We report a case of an 8-year-old girl with a right renal mass that initially was suspected to be a Wilms tumor based on imaging results and was treated with Wilms-directed chemotherapy without response. Histopathological investigations after a radical nephrectomy revealed an EAML composed primarily of epithelioid cells. Immunohistochemistry confirmed the diagnosis with positive results for HMB45 and Melan-A, highlighting the importance of histopathological and immunohistochemical evaluation in pediatric renal masses with atypical clinical behavior. Conclusion: Renal epithelioid angiomyolipoma should be considered in pediatric renal masses with atypical imaging features or poor response to Wilms tumor chemotherapy. Accurate diagnosis relies on histopathological and immunohistochemical evaluation, which helps guide appropriate surgical management and postoperative surveillance due to the tumor's variable malignant potential.