Yours truly presented a case of a middle aged man admitted for traumatic rib fracture overnight and found to have a WBC of 368k with cytogenetics consistent with CML!

Clinical Pearls

• WBC > 100k is most consistent with leukemia.
• WBC up to 75k can be seen with C diff infection.
• Leukostasis is most commonly associated with AML > ALL > CML > CLL and defined as hyperleukocytosis with evidence of end-organ damage (CNS, renal, pulm)
  • Hematologic emergency!
  • Treatment is three-fold:
    • cytoreduction: leukapharesis, hydroxyurea, TKI (especially for CML), induction chemo (with other malignancies)
    • FLUIDS
    • prevention of tumor lysis syndrome (another heme emergency): allopurinol, FLUIDS

Differential for leukocytosis:

• Neutrophilia (most common, >7000/mm^3)
  • Infections
  • Stress/trauma
  • Chronic inflammation
  • Meds
  • Leukemias
• Lymphocytosis (>4500/mm^3)
  • Pertussis
  • Syphilis
  • Viral infections
  • Hypersensitivity reactions
  • Leukemias/lymphomas
• Monocytosis (>880/mm^3)
  • EBV
  • TB
  • Fungal disease
  • Autoimmune disease
  • Splenectomy
  • Protozoan/rickettsial infections
  • Leukemias

   

• Eosinophilia (>500/mm^3):
  • Neoplasm
  • Adrenal insufficiency
  • Asthma/atopy
  • Collagen vascular disease
  • Parasites

CML:

• Refer to this and this prior posts on the blog for all the details!
• Some details to highlight
  • Smear tends to show lots of immature myeloid cells from many different stages of maturation (some blasts, metamyelocytes, myelocytes, bands, and mature neutrophils)
  • If >20% blasts, then think AML

Leukostasis:

• Defined as symptomatic hyperleukocytosis and is a hematologic emergency!
• Mortality rate is can be as high as 40% within the first week of presentation.
• Clinical manifestations of ischemia primarily in CNS, lungs, and kidneys.  Can also see limb ischemia and priapism.
• Malignancies at highest risk of leukostasis in order of prevalence:
  • AML (WBC >50k)
  • ALL (WBC >100k, though tends to present with TLS and DIC much more commonly than leukostasis)
  • CML (WBC >100k)
  • CLL (WBC >400k)
• Treatment:
  • FLUIDS, lots and lots of fluids
  • Cytoreduction: lowers the WBC
    • Leukapharesis: not readily available as it requires a dialysis line and trained nursing staff
    • Hydroxyurea: to lower the WBC
    • Tyrosine kinase inhibitors (especially for CML related leukostasis)
    • Induction chemo (for non-CML related leukostasis)
  • Prevent tumor lysis syndrome:
    • FLUIDS
    • Allopurinol
  • In hemodynamically stable patients AVOID TRANSFUSION – it’s like adding fuel to the fire and can worsen ischemia.