NOTE
🌱 created from: acute lymphoblastic leukemia
diagnosis_of_all
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B cell ALL is a malignancy of immature B cells. It is commonly seen in children, but a second peak in incidence is seen in adults who are > 60 years of age.
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Diagnosis of B-ALL/LBL requires demonstration of B-cell lymphoblasts that have a characteristic immunophenotype.
- In B-ALL, one will find that the B cell antigens are positive （CD19, CD79a, cytoplasmic CD22）. T cell antigens such as CD3 should be negative.
- Myeloid antigens （CD13 and CD33） may be expressed in B-ALL. However, if myeloperoxidase （MPO） is positive, it excludes the diagnosis of B-ALL/LBL.
- The immunophenotype of a blast can help determine the underlying malignancy. This patient has expression of the characteristic B-cell markers and not T-cell markers. AML would be unlikely for him given that he does not have the myeloid lineage markers.
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Blasts: CD34+, CD117+, CD123+, HLA-DR+
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Myeloid lineage (AML)：CD13+, CD33+, MPO+， CD11b+
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B-cell: CD19+, CD20+, CD22+, CD79+, PAX5+
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T-cell: CD2+, CD3+, CD5+, CD7+, CD30+
World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia
- NOS
- with t(9;22)(q34.1;q11.2);BCR-ABL1
- BCR-ABL1-like
- with t(v;11q23.3); KMT2A rearranged
- with t(12;21)(p13.2;q22.1);ETV6-RUNX1
- with t(5;14)(q31.1;q32.3) IL3-IGH
- with t(1;19)(q23;p13.3);TCF3-PBX1
- with recurrent genetic abnormalities
- with hyperdiploidy
- with hypodiploidy
- with iAMP21