Primary renal lymphoma: unique presentation in a rare disease.

As the kidney is an extra-nodal organ and does not have lymphatic tissues, the existence of primary renal non-Hodgkin's lymphoma has been continuously questioned. It is very rare. However, differentiation between renal cell carcinoma and renal lymphoma is necessary in patients presenting with solitary renal mass. We present a 70-year-old-man who presented with a renal mass and was diagnosed with diffuse large B-cell lymphoma. We feel that this case report may be of benefit to clinicians who may encounter a similar scenario.