B-cell lymphoma presenting as infiltrative renal disease.

Acute renal failure is rarely the presenting manifestation of non-Hodgkin's lymphoma. Of the reported cases of renal insufficiency secondary to diffuse renal infiltration with lymphoma, few have presented with acute renal failure. We present a patient with acute renal failure secondary to diffuse bilateral renal infiltration by a B-cell non-Hodgkin's lymphoma. The findings of an elevated serum lactate dehydrogenase (LDH), lymphopenia, and homogenous bilateral renal enlargement on computed tomographic (CT) imaging were important in suggesting the diagnosis of primary renal lymphoma. Renal biopsy with immunohistochemical and ultrastructural analysis was instrumental in confirming this diagnosis.