Acute renal failure secondary to spontaneous acute tumor lysis syndrome in myelofibrosis.

A 70-year-old man with myelofibrosis developed nonoliguric acute renal failure in association with acute uric acid nephropathy in the absence of chemotherapy or radiotherapy. The patient had an 18-month history of transfusion-dependent myelofibrosis and moderate chronic renal insufficiency. Admission laboratory findings were remarkable for severe hyperuricemia, hyperphosphatemia, hyperkalemia, and hypocalcemia with acute deterioration of renal function, consistent with a diagnosis of acute uric acid nephropathy. Treatment, including hemodialysis and allopurinol administration, resulted in clinical improvement with normalization of serum uric acid concentrations and resolution of acute renal failure. With long-term allopurinol therapy, renal function has remained at his previous baseline, and there has been no transformation to acute leukemia. This case represents a rare instance of acute renal failure related to the occurrence of acute uric acid nephropathy associated with myelofibrosis and emphasizes the importance of early recognition and aggressive management, which can lead to recovery of renal function.