Rapidly progressive renal failure in a patient with extranodal non-Hodgkin's lymphoma.

A 60-year male was admitted with advanced renal failure and bilaterally enlarged kidneys. Kidney biopsy revealed diffuse interstitial infiltration by CD20 + lymphomatous cells suggestive of diffuse large B-cell, non-Hodgkin's lymphoma. Bone marrow examination was negative for malignant cells. Positron emission tomography-computed tomography showed uniformly diffuse and avid flurodeoxy glucose uptake in both kidneys, multiple hypodense areas of both lobes of liver, and axial and appendicular skeleton. Patient was treated with rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine and prednisolone, became afebrile and serum creatinine normalized.