From the Guidelines
Erythroid leukemia is defined as a rare and aggressive form of acute myeloid leukemia (AML) characterized by the abnormal proliferation of immature red blood cell precursors, with diagnosis requiring bone marrow examination showing at least 50% erythroid precursors with at least 20% myeloblasts among non-erythroid cells, as per the World Health Organization classification system 1.
Key Characteristics
- Accounts for less than 5% of all AML cases
- Classified as acute erythroid leukemia in the World Health Organization classification system
- Characterized by genetic mutations causing erythroid precursor cells in the bone marrow to multiply uncontrollably and fail to mature properly
Diagnosis and Treatment
- Diagnosis requires bone marrow examination showing at least 50% erythroid precursors with at least 20% myeloblasts among non-erythroid cells
- Treatment generally involves intensive chemotherapy regimens similar to those used for other AML subtypes, potentially followed by stem cell transplantation in eligible patients
- Prognosis is generally poor compared to other forms of AML, with higher rates of treatment resistance and relapse, making early diagnosis and aggressive treatment essential 1
Important Considerations
- Patients typically present with symptoms of bone marrow failure including fatigue, weakness, frequent infections, and bleeding tendencies
- The World Health Organization classification system provides a framework for diagnosing and classifying erythroid leukemia, with specific criteria for assigning more than one lineage to a single blast population in mixed phenotype acute leukemia (MPAL) 1
From the Research
Definition of Erythroid Leukaemia
- Erythroid leukaemia is a rare and aggressive subtype of Acute Myeloid Leukemia (AML) 2.
- According to the World Health Organization (WHO), Acute Erythroid Leukemia (AEL) is defined as a biopsy with ≥30% proerythroblasts and erythroid precursors that account for ≥80% of cellularity 2, 3.
- The International Consensus Classification refers to this neoplasm as "AML with mutated TP53", which entails ≥20% blasts in blood or bone marrow biopsy and a somatic TP53 mutation (VAF > 10%) 2.
Subtypes of Erythroid Leukaemia
- Pure erythroid leukemia (PEL) is a rare and aggressive form of acute leukemia whose biology remains poorly characterized 4, 3.
- Erythroleukemia is another subtype of acute erythroid leukemia, although it was merged into myelodysplastic syndrome in the 2016 WHO update 4, 5.
Diagnostic Criteria
- The diagnosis of erythroid leukaemia is based on the presence of ≥30% proerythroblasts and erythroid precursors that account for ≥80% of cellularity in a bone marrow biopsy 2, 3.
- The International Consensus Classification also requires a somatic TP53 mutation (VAF > 10%) and ≥20% blasts in blood or bone marrow biopsy 2.