HWN Suggests

The White Count: Acute Hyperleukocytosis and Leukostasis

Hyperleukocytosis is arbitrarily defined as a WBC count greater than 100,000/ µL. Although there a few conditions that can present with elevated WBCs, hematologic malignancy tends to be the major cause of such an extremely elevated value. Hyperleukocytosis can be from a severe leukemoid reaction, which is when the WBC count is greater than 50,000/ µL in patients in whom leukemia has been ruled out. This can occur in infections (typically Clostridium difficile and disseminated tuberculosis), carcinomas, or severe hemorrhages. However, as mentioned, WBC counts higher than 100,000 is most prevalent in hematologic malignancies, mainly in acute myeloid leukemia (AML), chronic myeloid leukemia (CML)...

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 Blast Crisis and Hyperleukocytosis

To muddy the waters of diagnosis even more, 80% of these patients with hyperleukocytosis will be febrile from inflammatory processes and/or infection. This is why hyperleukocytosis and leukostasis should remain at the top of a physician’s differential.

Articles of Interest

Emergency Management of Blast Crisis

The majority of patients in blast crisis will often present with signs and symptoms related to pancytopenia (anemia, neutropenia, thrombocytopenia).

How I treat hyperleukocytosis in acute myeloid leukemia

Hyperleukocytosis (HL) per se is a laboratory abnormality, commonly defined by a white blood cell count >100 000/µL, caused by leukemic cell proliferation. Not the high blood count itself, but complications such as leukostasis, tumor lysis syndrome, and disseminated intravascular coagulation put the patient at risk and require therapeutic intervention.

Hyperleukocytosis and Leukostasis in the PICU

Generally avoid RBC transfusions as this can increase viscosity and exacerbate leukostasis

Leukapheresis and Hyperleukocytosis, Past and Future

Hyperleukocytosis is a hematologic crisis caused by excessive proliferation of leukemic cells and has a relatively high early mortality due to a series of severe complications. Therefore, prompt and effective intervention is required. The pathogenesis of hyperleukocytosis is still unclear.

What Is the Best Method for Cytoreduction in Patients With Acute Myeloid Leukemia and Hyperleukocytosis?

Two recent studies evaluated two standard approaches to cytoreduction – high-dose cyclophosphamide and leukapheresis – and seem to suggest that high-dose cyclophosphamide leads to a greater sustained reduction in WBC counts, while the benefits of leukapheresis were brought into question.

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WikEM

Hyperleukocytosis is lab abnormality of WBC >50-100K. Blood viscosity increases. Leukostasis is symptomatic hyperleukocytosis; it is a medical emergency