Hyperuricemia and acute renal failure secondary to spontaneous tumor lysis syndrome in myelodysplastic syndrome

Background: This is a rare instance of acute renal failure caused by hyperuricemia due to spontaneous tumor lysis syndrome and the first case of spontaneous tumor lysis syndrome reported in myelodysplastic syndrome. Case Presentation: A 53-year-old man presented with abrupt oligouria. Laboratory findings on admission suggested hyperuricemia, hyperphosphatemia, hypocalcinemia, metabolic acidosis and rapidly elevated serum creatinine, which were consistent with acute tumor lysis syndrome in the absence of precipitating chemotherapy or radiotherapy. After hemodialysis and oral uric acid lowering therapy, the serum uric acid levels returned to normal range and the renal function rapidly recovered. The patient was diagnosed myelodysplastic syndrome eleven months later. Conclusion: Occult malignancy including solid tumors and hematological malignancies should be carefully evaluated in the case of unexplainable acute renal failure with hyperuricemia. Aggressive examinations should be thoroughly considered and repeated as necessary in this population.