Typically occurs within 1 to 5 days of initiation of chemotherapy
Associated with treatment of acute leukemia, Burkitt lymphoma, NHL
Rarely observed in solid<unk> s or without prior therapy
Rapid turnover of<unk>  cells (spontaneously or after treatment) leading to release of:
Potassium
Phosphate
Binds Ca causing hypocalcemia
Uric acid (converted from nucleic acids)
Rarely observed in solid<unk> s or without prior therapy
Potassium
Phosphate
Binds Ca causing hypocalcemia
Uric acid (converted from nucleic acids)
Binds Ca causing hypocalcemia
High cell proliferation rate
Large<unk>  burden (LDH) > 1500 IU/L, WBC ≥ 50 x 103 cells/L
Extensive BM involvement<unk>  infiltration of the kidney
Laboratory<unk> 
Abnormality in 2 or more of the following, occurring within 3d before or 7d after chemo:
Uric acid ≥ 8mg/dL or 25% increase from baseline
Potassium ≥ 6mEq/L or 25% increase from baseline
Phosphate ≥ 4.5mg/dL or 25% increase from baseline (≥ 6.5 for children)
Calcium ≤ 7mg/dL or 25% decrease from baseline
Uric acid ≥ 8mg/dL or 25% increase from baseline
Potassium ≥ 6mEq/L or 25% increase from baseline
Phosphate ≥ 4.5mg/dL or 25% increase from baseline (≥ 6.5 for children)
Calcium ≤ 7mg/dL or 25% decrease from baseline
Clinical<unk> 
Laboratory<unk>  plus 1 or more of the following:
Creatinine > 1.5 times upper limit of age-adjusted reference range
Cardiac dysrhythmia or sudden death
Seizure
Creatinine > 1.5 times upper limit of age-adjusted reference range
Cardiac dysrhythmia or sudden death
Seizure
Tumor lysis syndrome
Malignant airway obstruction
Sepsis 
Bone metastases and pathologic fractures
Hemorrhagic shock
Malignant spinal cord compression
Neurogenic shock
Malignant Pericardial Effusion and Tamponade