Tumor lysis syndrome in children with acute leukemia: Incidence and outcome

Background: Tumor lysis syndrome (TLS) comprises a number of metabolic and renal abnormalities of variable spectrum. It is associated with lymphoproliferative disorder e.g., acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma (NHL). The aim of this study to evaluate the incidence, severity and outcome in Saudi children with ALL. Methods: Medical records of Children age <14 years and diagnosed with ALL were reviewed. We adopted the Hande and Garrow definitions for tumor lysis Syndrome. All patients received hydration, alkalinization with sodium bicarbonate and allopurinol as prophylaxis. Results: Seventy-four patients developed TLS (19% of all patients). Boys were affected than girls with ratio of 2.4:1. LTLS occurred in 93.3% and CTLS in 6.7%. Hyperphosphatemia was found in 94.6% of the patients. Hyperkalemia occurred only in 17 patients (23%). Hypokalemia was found in significant number of patients (12%). Lymphomatous presentation was seen in 60 patients (82%). Hemodialysis was required in 5 patients (6.6%) and 4 of them had hyperleukocytosis. There were no deaths encounterd due to TLS. Male sex, lymphomatous presentation, high LDH, high pretreatment WBC and central nervous system involvement were found to have statistical significance as risk factors for TLS development.Conclusion: TLS is a common event in childhood ALL. Spontaneous TLS indicate highly proliferating tumor and possible delayed presentation to our institute. Prophylactic measures are important to improve the outcome particularly when initiated as soon as the diagnosis is established.