Atypical Presentation of Tumor Lysis Syndrome Complicated by Rasburicase-Induced Methemoglobinemia.

Tumor lysis syndrome (TLS) is a life-threatening metabolic disorder caused by the rapid breakdown of malignant cells, usually associated with chemotherapy treatment. It can lead to electrolyte imbalances, such as hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. These disturbances can lead to complications, including acute renal failure, cardiac arrhythmias, and seizures. TLS typically presents in patients with hematologic malignancies; however, there has been an increase in cases in the context of solid tumors with comorbid conditions, bulky tumors, or dehydration. This report presents a case of TLS in an approximately 65-year-old female with stage IV squamous cell carcinoma of the cervix who developed acute kidney injury, lactic acidosis, and hyperuricemia following chemotherapy with docetaxel. Despite the absence of classic electrolyte abnormalities, her clinical decompensation raised suspicions of TLS. The patient was treated with rasburicase for hyperuricemia, from which she developed methemoglobinemia, a rare complication in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. This case highlights the challenges in diagnosing atypical presentation of TLS in solid tumor patients. It also emphasizes the rare but serious complications of raburicase in G6PD-deficient individuals, such as methemoglobinemia. Further research into TLS in solid tumors and the role of G6PD screening in preventing adverse drug reactions in at-risk populations would be beneficial in these cases. Early recognition, rapid testing, and individualized treatment strategies are essential for patient care in these complex clinical scenarios.