Concurrent angiomyolipoma and two oncocytomas in the same kidney

We report on a rare case of synchronous angiomyolipoma (AML) and 2 oncocytomas (OCs) in the same kidney of a 73-year-old woman. During the course of a follow-up for a long-standing staghorn calculus in the left kidney, a 4-cm right suprarenal mass and a small solid nodule adjacent to a cyst in the midportion of the right kidney were radiographically discovered. A radical nephrectomy was performed. The suprarenal tumor was found to be an AML, and the small nodule was an OC (1.5 cm). An additional OC (0.8 cm) elsewhere in the right kidney was also identified. The coexistence of AML and other renal tumors is uncommon. Among reported cases, conventional renal cell carcinoma, possibly reflecting its higher incidence, has been the most common concurrent tumor with AML. Although only rare cases of simultaneous AML and OC have been reported in the literature, it appears that the proportion of OC among concurrent renal tumors with AML is higher than expected based on its frequency among all surgically resected renal neoplasms. Whether there is a pathogenetic association between AML and OC needs to be further investigated.