The tumor lysis syndrome (TLS) is a common emergency in patients with hematologic cancers, occurring when tumor cells release their contents into the bloodstream, leading to hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. These electrolyte imbalances can progress to severe complications like renal failure, cardiac arrhythmias, and death. TLS is increasingly seen in patients with cancers previously not associated with this complication, such as endometrial cancer and hepatocellular carcinoma. TLS is classified as laboratory or clinical, with clinical TLS involving additional symptoms like increased creatinine, seizures, or death. Risk factors include preexisting renal insufficiency, dehydration, and acidic urine. TLS management focuses on preventing renal injury and dysrhythmias. Intravenous hydration is crucial to improve renal perfusion and reduce acidosis. Allopurinol and rasburicase are used to lower uric acid levels, with rasburicase being more effective in preventing TLS. Fluid management and monitoring urine output are essential. Patients with high risk should receive rasburicase, while those at lower risk may be managed with fluids and allopurinol. Dialysis may be required in severe cases, but it is avoided when rasburicase is available. TLS can be prevented by early risk assessment, hydration, and prophylactic therapy. Risk stratification models are being developed, but standardized guidelines are still evolving. TLS is associated with significant morbidity and mortality, and early recognition is critical. The case of an 8-year-old boy with TLS highlights the importance of timely intervention, as his condition was managed with fluids, rasburicase, and phosphate binders, preventing dialysis and long-term remission. The syndrome is often linked to cancer cell lysis, releasing potassium, phosphorus, nucleic acids, and cytokines, which can cause acute kidney injury and other systemic effects. Effective management requires a multidisciplinary approach, including monitoring electrolytes, renal function, and cardiac status. The use of rasburicase has significantly improved outcomes in TLS, particularly in pediatric patients.The tumor lysis syndrome (TLS) is a common emergency in patients with hematologic cancers, occurring when tumor cells release their contents into the bloodstream, leading to hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. These electrolyte imbalances can progress to severe complications like renal failure, cardiac arrhythmias, and death. TLS is increasingly seen in patients with cancers previously not associated with this complication, such as endometrial cancer and hepatocellular carcinoma. TLS is classified as laboratory or clinical, with clinical TLS involving additional symptoms like increased creatinine, seizures, or death. Risk factors include preexisting renal insufficiency, dehydration, and acidic urine. TLS management focuses on preventing renal injury and dysrhythmias. Intravenous hydration is crucial to improve renal perfusion and reduce acidosis. Allopurinol and rasburicase are used to lower uric acid levels, with rasburicase being more effective in preventing TLS. Fluid management and monitoring urine output are essential. Patients with high risk should receive rasburicase, while those at lower risk may be managed with fluids and allopurinol. Dialysis may be required in severe cases, but it is avoided when rasburicase is available. TLS can be prevented by early risk assessment, hydration, and prophylactic therapy. Risk stratification models are being developed, but standardized guidelines are still evolving. TLS is associated with significant morbidity and mortality, and early recognition is critical. The case of an 8-year-old boy with TLS highlights the importance of timely intervention, as his condition was managed with fluids, rasburicase, and phosphate binders, preventing dialysis and long-term remission. The syndrome is often linked to cancer cell lysis, releasing potassium, phosphorus, nucleic acids, and cytokines, which can cause acute kidney injury and other systemic effects. Effective management requires a multidisciplinary approach, including monitoring electrolytes, renal function, and cardiac status. The use of rasburicase has significantly improved outcomes in TLS, particularly in pediatric patients.