Acute renal failure due to a malignant lymphoma infiltration uncovered by renal biopsy

Renal involvement by large B-cell lymphoma represents an exceptional manifestation of non-Hodgkin lymphoma. Acute renal failure (ARF) by a lymphoma infiltration of the kidney is extremely rare (so far 11 cases have been reported in the literature). We report a patient who was hospitalized for upper GI bleeding. Clinical examination revealed a tumour of the os sacrum. A CT-guided needle biopsy led to the diagnosis of a sarcoma. At this time, progressive renal failure was observed. Ultrasound showed enlarged kidneys with normal arterial and venous perfusion conditions. No urinary tract obstruction was detected. The cause of ARF was diagnosed by renal biopsy to be a diffuse infiltration of a large B-cell non-Hodgkin lymphoma. The re-evaluation of the primary histology of the os sacrum confirmed the renal biopsy diagnosis of the B-cell lymphoma. Subsequent staging showed an additional lymphoma infiltration of the lung and liver, but no bone marrow infiltration. Adequate dose-adjusted chemotherapy (CHOP) led to recovery of renal function in the follow-up. This report shows the importance of a renal biopsy in the work-up of ARF even in patients with known malignant diseases. Case