Onc Emergency

Question 1

Hyperleukocytosis

Answer 1

WBC counts greater than 100,000/mm3 are associated with the clinical syndrome of
hyperleukocytosis, especially when the cause of the elevated white count is acute myeloid
leukemia.

Clinical features of hyperleukocytosis can include CNS findings (eg, lethargy, focal
neurologic deficits, intracranial bleeding, hemorrhagic stroke), respiratory findings (tachypnea,
dyspnea, hypoxia, and diffuse interstitial infiltrates), and renal dysfunction (often complicated by
concomitant tumor lysis syndrome).

Hyperleukocytosis is a medical emergency that requires immediate “debulking” of the
circulating tumor burden, which is best accomplished by manual exchange transfusion or by
leukapheresis. Initiation of chemotherapy should proceed as soon as possible but should not be
the first step in management.