Metanephric adenoma. A case report and literature review

Metanephric adenoma is a rare renal tumor with almost exclusively benign behavior, which can clinically and radiologically imitate malignancy. The histological examination is therefore crucial in diagnosis. We report a case of a 69-year-old female with an incidental finding of metanephric adenoma of the left kidney and synchronous clear cell renal cell carcinoma of the contralateral kidney. In the report, we present our experience with this rare tumor and literature review with focusing on differential diagnosis. The histological differential diagnosis of metanephric adenoma includes papillary renal cell carcinoma in adult patients and nephroblastoma (Wilms tumor), particularly in children. Immunohistochemical examination and cytogenetic analyses may be useful in differential diagnosis of these neoplasms.