Patients with a high tumor burden may develop tumor lysis syndrome. Tumor lysis syndrome consists of at least 2 metabolic abnormalities, which may include hyperkalemia, hyperphosphatemia, or hyperuricemia. The goal of standard therapy is to prevent tumor lysis syndrome. Prophylactic therapy includes hydration, alkalinization, and treatment to lower uric acid with either allopurinol or rasburicase. Other metabolic abnormalities are treated as they occur.