[An exceptionally severe hyperuricemia in acute renal failure caused by spontaneous tumor lysis syndrome (TLS)].

Acute tumor lysis syndrome (TLS) is a catastrophic complication of the treatment of certain neoplastic disorders. It most commonly occurs in association with hematologic malignancies and manifests a few hours to a few days after initiation of specific chemotherapy. Acute spontaneous TLS has been described in leukemia and lymphoma and in some patients with solid tumors prior to institution of therapy. The findings that may be seen in acute TLS include hyperphosphatemia, hypocalcemia, hyperuricemia, hyperkalemia, and acute oliguric or anuric renal failure due to uric acid precipitation within the tubules (acute uric acid nephropathy) and to calcium phosphate deposition in the renal parenchyma and vessels. We report here a case of acute spontaneous TLS (high grade B-cell lymphoma of the right colon) in which serum uric acid concentration attained exceptionally high levels (36.7 mg/dL). The patient underwent acute oliguric renal failure soon after right colectomy. He was treated by means of a large infusion of saline. The renal function recovered in such a rapid way that no dialysis treatment was required. In conclusion the present case report has two peculiarities: that of being one of the rare examples of spontaneous TLS, and that of showing an exceptionally severe hyperuricemia, probably the highest ever reported in the literature. The administration of a large volume of saline was able to ensure a complete recovery of renal function. Therefore, hydration with saline remains the keystone in the prevention and treatment of acute TLS.