Metanephric adenoma: a rare benign renal tumour

Metanephric adenoma is a rare benign renal tumour. We are reporting one histologically proven such case in a 23 year old male from Afghanistan. He presented with severe right flank pain since 3 weeks. Nephrectomy was done and histopathology was consistent with the diagnosis of metanephric adenoma. This novel renal mass has been reported to have benign clinical course despite its symptomatic presentation and large tumour size. There is no distinguishing radiological feature with can differentiate it from malignant tumours. So far, a uniformly benign clinical course has been associated with Metanephric adenoma, but given its relatively recent identification and rarity and the lack of clinical, radiographic, or cytologic means to establish a definite diagnosis, Metanephric adenoma remains primarily a pathologic diagnosis.