Sepsis-induced Hyperleukocytosis in a Preterm.

Hyperleukocytosis is defined as a white blood cell (WBC) count of ≥ 100,000/µL. Leukostasis refers to symptomatic hyperleukocytosis and is considered a medical emergency. In pediatric practice, hyperleukocytosis is most commonly described in leukemia and other myeloproliferative disorder, but other etiologies, such as infection, are less commonly mentioned.