Rasburicase Treatment for Chemotherapy or Malignancy-Induced Hyperuricemia in Asthma/Allergy Patients

Inclusion Criteria: * A diagnosis of hematologic malignancy. * Existing hyperuricemia or high risk of developing hyperuricemia of malignancy. * The treating clinician plans to treat the patient with rasburicase. A patient is only eligible for RASALL if the clinician has already decided to use rasburicase. Rasburicase should not be given in order to make a patient eligible for this non-therapeutic observational study. * No prior exposure to rasburicase or other urate oxidase. * A history of asthma or significant allergy. Exclusion Criteria * Wheezing or an active hypersensitivity reaction at entry. * Hypersensitivity to Aspergillus proteins.