Large Cystic Metanephric Adenoma in a 15-Year-Old Girl.

Metanephric adenoma is a rare pediatric renal tumor, generally considered to be benign. It can be difficult to distinguish from Wilms tumor and renal cell carcinoma based on imaging alone, and even may be difficult on histopathologic analysis. We present a case of a large cystic metanephric adenoma managed with surgical resection. This case highlights the difficulty in managing cystic renal lesions in children and adolescents as there is a paucity of data on the radiologic and pathologic correlation in such patients.