2. Risk of TLS: A. High risk: hyperuricemia of malignancy; diagnosis of aggressive lymphoma/leukemia based on Revised European-American Lymphoma (REAL) classification; acute myeloid leukemia in blast crisis; high grade myelodysplastic syndrome only if they have >10% bone marrow blast involvement and given aggressive treatment similar to AML; OR B. Potential risk: diagnosis of aggressive lymphoma/leukemia based on (REAL) classification. Plus one or more of the following criteria: LDH >/=2 x ULN; Stage III-IV disease; Stage I-II disease with at least 1 lymph node/tumor >5cm in diameter.