Acute renal failure due to lymphomatous infiltration of the kidneys.

Acute renal failure (ARF) is an unusual manifestation of lymphomatous infiltration of the kidneys. In this article, a patient whose initial presentation of lymphoma was the sudden onset of painless hematuria and ARF is described. The absence of other causes of ARF, together with massively enlarged unobstructed kidneys on renal ultrasonography, strongly suggested an infiltrative process. Renal biopsy established the diagnosis of non-Hodgkin's lymphoma. Pulse steroid therapy was associated with rapid improvement of renal function and kidney size, but a moderate degree of tumor lysis syndrome ensued. Further recovery followed with chemotherapy. Whereas widespread infiltration of the kidneys is present in almost one third of patients with lymphoma at autopsy, this rarely causes clinical symptoms. Nevertheless, because it often responds to therapy, lymphomatous infiltration should be suspected in any patient presenting with unexplained ARF and enlarged kidneys, especially in the setting of widespread lymphoma.