Background: Oncocytomas are benign tumors of the kidney that are usually diagnosed postoperatively due to differential diagnostic problems from renal cell carcinoma. Although the latter are neoplasms that have been associated with erythrocytosis in 3.5% of cases, there are no reports in the literature about a similar occurrence in oncocytomas.
Case presentation: In this case report we present a unique case of a right lower pole oncocytoma associated with erythrocytosis. Erythrocytosis subsided after partial nephrectomy.
Conclusion: Erythrocytosis can sometimes occur in association with renal oncocytomas.