Hyperleukocytosis in cancer patients

Hyperleukocytosis is characterized by rapid cell turnaround (mature and immature) with peripheral blood white blood cell (WBC) count exceeding 100,000 x 10⁹/L in association with a malignant clone. High WBC count can lead to many lethal complications of which leukostasis, disseminated intravascular coagulation (DIC), and tumor lysis syndrome (TLS) are predominant. Symptomatic hyperleukocytosis portends poor prognosis, reflecting the aggressive nature of the biologic drivers behind this entity, and warrants emergent therapeutic interventions. In managing hyperleukocytosis, aggressive supportive care measures, leukapheresis, and hydroxyurea could be utilized until definitive therapy can be initiated to alter the symptomatic course of disease and its complications. Metabolic and coagulation abnormalities need to be frequently scrutinized and rapidly corrected to permit definitive therapy and prevent avoidable complications.