Morphological and Immunophenotypic Clues to the WHO Categories of Acute Myeloid Leukaemia

Area of Science:

• Hematology
• Oncology
• Cytogenetics

Background:

• Accurate diagnosis of acute myeloid leukaemia (AML) relies on cytogenetic and molecular genetic analysis.
• These genetic investigations are crucial for classifying AML subtypes and guiding treatment decisions.
• However, results from genetic testing can take time, necessitating alternative diagnostic approaches.

Purpose of the Study:

• To evaluate the utility of morphology and immunophenotyping in the provisional diagnosis of AML subtypes while genetic analyses are pending.
• To determine the effectiveness of these methods in identifying specific genetic abnormalities and conditions associated with AML.
• To highlight the diagnostic value of morphological assessment for certain AML categories.

Main Methods:

• Review of morphological features of leukaemic cells under microscopy.
• Application of immunophenotyping techniques to identify cell surface markers.
• Correlation of morphological and immunophenotypical findings with pending cytogenetic and molecular genetic results.

Main Results:

• Morphology and immunophenotyping can suggest specific cytogenetic/genetic categories of AML.
• Acute promyelocytic leukaemia can be diagnosed with high diagnostic certainty using these methods.
• Provisional identification of AML cases with t(8; 21), inv(16), t(1; 22), and NPM1 mutations is possible.
• Transient abnormal myelopoiesis associated with Down's syndrome is generally diagnosable morphologically.

Conclusions:

• Morphology and immunophenotyping are valuable adjunctive tools for the early diagnosis and classification of AML.
• These methods can provide crucial diagnostic clues, especially for acute promyelocytic leukaemia and other specific genetic subtypes.
• Early diagnostic insights facilitate timely clinical management while definitive genetic results are obtained.