Extreme leucocytosis: not always leukaemia

Area of Science:

• Hematology
• Oncology
• Infectious Diseases

Background:

• Leukocytosis, an elevated white blood cell count, can be a concerning sign in clinical practice.
• Leukemia is a primary concern when extreme leukocytosis is observed.
• Distinguishing between neoplastic and reactive causes of leukocytosis is crucial for appropriate patient management.

Observation:

• Three patients presented with extreme leukocytosis (>50x10(9)/l), initially suspected to be leukemia.
• In all cases, the elevated white blood cell count was attributed to a leukaemoid reaction, not leukemia.
• The leukaemoid reactions were linked to diverse underlying conditions: hepatic angiosarcoma, Salmonella infection, and a necrotic leg abscess.

Findings:

• A retrospective analysis identified 25 cases of leukaemoid reactions over a four-year period.
• Leukaemoid reactions can mimic leukemia, presenting a diagnostic challenge.
• These reactions are often associated with severe underlying pathologies.

Implications:

• Extreme leukocytosis necessitates consideration of leukaemoid reactions alongside leukemia in the differential diagnosis.
• Early identification of the underlying cause of leukaemoid reactions is critical, as they can indicate serious conditions.
• Recognizing leukaemoid reactions can guide further diagnostic workup and treatment strategies, potentially improving patient outcomes.