The flow cytometric diagnosis of AML

Acute leukaemia types

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For most cases, the diagnosis of AML by flow cytometry is relatively straightforward. The problem lies in atypical cases and unusual diagnoses that may be missed.

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1. The immunophenotype of AML blasts will (generally) reflect their primitive nature
The typical "primitive" morphology of blast cells is generally accompanied by signs of primitive immunophenotype

• Most often in AML typical features of immature cells will be found with: weak expression of CD45, together with expression of CD34 and/or CD117. Other markers may be useful in difficult cases (see Click for more detailed description)
• However in cases where blast cells show more differentiation their nature may be less clear. This is most frequently encountered in monocytic cases of AML or in APL (Click for a more detailed description)

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2. The cases should express sufficient markers to allow myeloid lineage to be assigned

• Typical cases can generally be recognised by (see table for details)
• Atypical cases can still be identified based on a minimal feature set (see table for details)
• In unusual cases an extended marker panel may allow lineage assignment (see Table for details)

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Are there atypical features?

• Expected abberency
• Feature that may give concern

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