Leukostasis and hyperleukocytosis

(Redirected from Leukostasis)


  • Hyperleukocytosis is lab abnormality of WBC >50-100K
  • Blood viscosity increases
  • Leukostasis is symptomatic hyperleukocytosis; it is a medical emergency
    • Most commonly seen with AML or CML in blast crisis
    • High blast cell count > WBC plugs in microvasculature
      • Brain and lung are most commonly affected
  • 20-40% of patients with leukostasis die within 1st week of presentation

Clinical Features

Differential Diagnosis

Oncologic Emergencies

Related to Local Tumor Effects

Related to Biochemical Derangement

Related to Hematologic Derangement

Related to Therapy



  • CBC
  • DIC labs
    • DIC occurs in up to 40% of patients
    • FDP, d-dimer, fibrinogen, coags
  • Tumor Lysis Syndrome labs
    • TLS occurs in up to 10% of patients
    • Chemistry
    • Uric acid
    • Calcium
    • Phosphate


  • High degree of suspicion needed to make the diagnosis
  • WBC count usually >100K; can have symptoms with WBC as low as 50K
  • CXR
    • Interstial or alveolar infiltrates


  • Hyperleukocytosis (asymptomatic)
  • Leukostasis
    • IV hydration
      • Prevent dehydration which can worsen condition
    • Chemotherapy
      • Only treatment proven to improve survival
    • Hydroxyurea + leukapheresis
      • Can be use for cytoreduction if chemo will be delayed
  • Allopurinol may help prevent Tumor lysis syndrome
  • Consider rasburicase
  • Broad spectrum antibiotics
    • The leading cause of death in blast crisis is infection (patients are functionally neutropenic)


  • Admit to ICU