Primary renal lymphoma: a case report and literature review.

Primary renal lymphoma (PRL) is a rare disease which is often mistaken for renal cell carcinoma. In the present study, a 56-year-old man visited a clinic complaining of an intermittent fever and right flank pain. A computerized tomography examination revealed a hypoenhancing mass in his right kidney. Radical nephrectomy was conducted, and a diagnosis of diffuse large B-cell lymphoma was confirmed. The present case was determined to be a true PRL according to the results of a positron emission tomography examination and a bone marrow biopsy to rule out any lymphoma invasions apart from the right kidney.