Clinical characteristics and complications in children and adolescents with hyperleukocytic acute leukemia.

Introduction. Hyperleukocytic acute leukemia is a pediatric hematological-oncological emergency associated with high morbidity and mortality. Objective. To describe the clinical and hematological characteristics, complications, and treatments of patients with acute hyperleukocytic lymphoblastic or myeloid leukemia. Population and methods. Descriptive, retrospective, cross-sectional study conducted in a tertiary pediatric hospital between January 1, 2020, and December 31, 2024. Results. Twenty-one patients <15 years of age diagnosed with hyperleukocytic leukemia were analyzed. Fifty-six percent had type B acute lymphoblastic leukemia, and 62% had extramedullary manifestations such as hepatomegaly and splenomegaly. The most common complications were tumor lysis syndrome (71%) and leukostasis (28%); 76% received rasburicase, and 1/3 required leukapheresis; 90% began chemotherapy within the first 2 days of hospitalization. There was a single early death due to hemorrhage in the central nervous system. Conclusion. The importance of early diagnosis and intensive initial management to improve the clinical outcomes of these high-risk patients is highlighted.