Acute kidney injury as first presentation of lymphoma: the role of renal biopsy.

A 65-year-old man with an insidious history of being generally unwell with weight loss, a poor appetite and night sweats was transferred to a tertiary nephrology unit after being found to be in acute kidney injury (AKI). A renal biopsy was performed on the same day which revealed lymphomatous infiltration of the renal parenchyma. He required temporary haemodialysis as he was oliguric and was started on chemotherapy. His renal function improved to baseline 3 weeks after treatment. This case illustrates the uncommon presentation of direct lymphomatous infiltration as a cause of AKI and the integral role of renal biopsy in ascertaining the diagnosis.