Professional
Technical
In the Industry Vocabulary Test
hyperleukocytosis
Pronunciation: hy-per-loo-koh-sy-TOH-sis
Extremely high white blood cell count requiring urgent intervention to prevent life-threatening complications.
Full Definition
Hyperleukocytosis is defined as a white blood cell count greater than 100,000 per microliter, representing a medical emergency in pediatric leukemia. This condition can lead to leukostasis, where high numbers of blast cells cause vascular occlusion in vital organs, particularly the brain and lungs. Immediate interventions may include leukapheresis, aggressive hydration, and prompt initiation of chemotherapy. Hyperleukocytosis is associated with increased risk of tumor lysis syndrome and CNS complications.
Usage
Usage note: Threshold of >100,000/μL distinguishes from standard leukocytosis.
In Context
- "Hyperleukocytosis at presentation required immediate leukapheresis." — emergency department note
- "The risk of CNS complications increases significantly with hyperleukocytosis." — treatment protocol
Also known as
high white cell count emergency
Contrasted with
leukopenia
cytopenia
Don't confuse with
lymphocytosis
leukocytosis