hyperleukocytosis
Pronunciation: hy-per-loo-koh-sy-TOH-sis
An extremely high white blood cell count, typically >100,000/μL, that constitutes a medical emergency due to risk of leukostasis and organ dysfunction.
Full Definition
Hyperleukocytosis is defined as a white blood cell count exceeding 100,000/μL and represents a hematologic emergency, particularly in acute leukemia. The condition can lead to leukostasis, where blast cells aggregate in small vessels, causing impaired blood flow and tissue hypoxia. This is especially dangerous in the central nervous system and lungs, potentially leading to intracranial hemorrhage, respiratory distress, or multi-organ failure. Immediate treatment typically involves leukapheresis or exchange transfusion to rapidly reduce the white cell count, along with aggressive hydration and tumor lysis syndrome prophylaxis. The risk of complications is higher with acute myeloid leukemia blasts due to their larger size and greater adherence properties.
Usage
Usage note: Always specify the white cell count when documenting; emphasize emergency nature of condition.
In Context
- "The patient presented with hyperleukocytosis and neurological symptoms requiring emergency leukapheresis." — hematology oncology consultation
- "Hyperleukocytosis with respiratory distress necessitated immediate intensive care unit admission." — emergency department note