Tumor lysis syndrome(TLS) has been broadly defined as the metabolic abnormalities that occur after rapid tumor breakdown. The purpose of this study was to evaluate the types or degrees of metabolic abnormalities and clinical characteristics in patients with high-grade non-Hodgkin's lymphoma(NHL) who developed clinical TLS.

Patients were considered to have 'clinical TLS' if two of the following metabolic abnormalities occurred within 4 days of treatment : a 25% increase in the serum phosphate, potassium, uric acid, urea nitrogen concentrations, or a 25% decline in the serum calcium concentration and one of the following : a serum potassium level greater than 6.0mEq/L, a creatinine level greater than 2.5mg/dL, a calcium level less than 6.0mg/dL, the development of a life-threatening arrhythmia, or sudden death.

Clonical TLS occurred in 15 patients with advanced high-grade NHL, and these patients were associated with elevated lactate dehydrogenase(LDH) and β₂-mivtonlonulin(MG)levels. Pre-treatment TLS occurred in 10 patients(66.7%) and post-treatment TLS in 5 patients(33.3%). Most of these patients showed metabolic abnormalities including hyperuricemia, hyperphosphatemia, hypocalcemia, or acute renal insufficiency. They were treated with adequate hydration combined with allopurinol and recovered in 4 patients. In remained 11 patients, hemodialysis was required and the metabolic parameters returned to normal levels without any significant complications.

It is important to remember that patients with advanced high-grade NHL who have more increased serum LDH or β₂-MG level be carefully monitored. Further investigations of elucidating risk factors and diagnostic criteria on clinical TLS will be required.