Imatinib Induced Tumor Lysis Syndrome in a Patient with Gastrointestinal Stromal Tumor

Tumor Lysis syndrome (TLS) is a well-known oncological emergency. It is most commonly associated with bulky and highly proliferative tumors such as leukemias and lymphomas where destruction of cells, usually from chemotherapy, leads to hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia. Such metabolic derangements can lead to renal failure and potentially fatal cardiac arrhythmias. New biologically directed therapies such as imatinib mesylate, a selective tyrosine kinase inhibitor against the proto-oncogene c-kit, may make TLS more common. We present a case of a patient with progressive metastatic gastrointestinal stromal tumor who, during treatment with imatinib mesylate, developed severe TLS ultimately leading to death. This case outlines the importance of clinicians to ensure appropriate monitoring of patient’s metabolic status during treatment with cytotoxic chemotherapy and biologically directed therapies, including oral agents such as imatinib, and to consider rasburicase or allopurinol and hydration as prophylaxis in high-risk populations.