Acute lymphoblastic leukemia Acute myeloid leukemia Acute leukemias of ambiguous lineage and biphenotypic leukemia WHO 2008 B lymphoblastic leukemia/lymphoma Acute myeloid leukemia and related neoplasms Acute leukemias of ambiguous lineage (i) B lymphoblastic leukemia/lymphoma, NOS (i) Acute myeloid leukemia with recurrent genetic abnormalities (i) Acute undifferentiated leukemia (ii) B lymphoblastic leukemia/lymphoma with recurrent genetic abnormalities AML with t(8;21)(q22;q22); RUNX1-RUNX1T1 (ii) Mixed phenotype acute leukemia with t(9;22)(q34;q11.2); BCR-ABL1 B lymphoblastic leukemia/lymphoma with (9;22)(q34;q11.2); BCR-ABL 1 AML with inv(16)(p13.1q22) or t(16;16)(p13.1;q22); CBFB-MYH11 (iii) Mixed phenotype acute leukemia with t(v;11q23); MLL rearranged B lymphoblastic leukemia/lymphoma with t(v;11q23); MLL rearranged APL with t(15;17)(q22;q12); PML-RARA (iv) Mixed phenotype acute leukemia, B-myeloid, NOS B lymphoblastic leukemia/lymphoma with t(12;21)(p13;q22) TEL-AML1 (ETV6-RUNX1) AML with t(9;11)(p22;q23); MLLT3-MLL (v) Mixed phenotype acute leukemia, T-myeloid, NOS B lymphoblastic leukemia/lymphoma with hyperdiploidy AML with t(6;9)(p23;q34); DEK-NUP214 (vi) Provisional entity: natural killer (NK) cell lymphoblastic leukemia/lymphoma B lymphoblastic leukemia/lymphoma with hypodiploidy AML with inv(3)(q21q26.2) or t(3;3)(q21;q26.2); RPN1-EVI1 B lymphoblastic leukemia/lymphoma with t(5;14)(q31;q32) IL3-IGH AML (megakaryoblastic) with t(1;22)(p13;q13); RBM15-MKL1 B lymphoblastic leukemia/lymphoma with t(1;19)(q23;p13.3); TCF3-PBX1 Provisional entity: AML with mutated NPM1 T lymphoblastic leukemia/lymphoma Provisional entity: AML with mutated CEBPA (ii) Acute myeloid leukemia with myelodysplasia-related changes (iii) Therapy-related myeloid neoplasms (iv) Acute myeloid leukemia, not otherwise specified AML with minimal differentiation AML without maturation AML with maturation Acute myelomonocytic leukemia Acute monoblastic/monocytic leukemia Acute erythroid leukemia Pure erythroid leukemia Erythroleukemia, erythroid/myeloid Acute megakaryoblastic leukemia Acute basophilic leukemia Acute panmyelosis with myelofibrosis (v) Myeloid sarcoma (vi) Myeloid proliferations related to Down syndrome Transient abnormal myelopoiesis Myeloid leukemia associated with Down Syndrome (vii) Blastic plasmacytoid dendritic cell Neoplasm FAB L1: lymphoblasts are usually smaller, with scanty cytoplasm and inconspicuous nucleoli
M0: undifferentiated. Undifferentiated, large, agranular blasts; >90% blasts MPO−; SBB− L2: lymphoblasts are larger, and they demonstrate considerable heterogeneity in size, prominent nucleoli and more abundant cytoplasm M1: acute myeloblastic, no maturation. Undifferentiated; >90% blasts; <10% promyelocytes/monocytes. MPO+;SSB+; PAS− L3: lymphoblasts notable for their deep cytoplasmic basophilia, large, frequently display prominent cytoplasmic vacuolation, morphologically identical to Burkitt’s lymphoma cells M2: acute myeloblastic with maturation. ≥30% and ≤89% blasts; >105 promyelocytes, myelocytes; <20% monocytic cells. MPO+; SSB+; PAS− M3: acute promyelocytic-hypergranular type. >20% abnormal hypergranular promyelocytes; Auer rods common. MPO+; SSB+; PAS− M3v: acute promyelocytic-hypogranular variant. Fine granularity of cytoplasm in promyelocytes; folded nuclei. MPO+; SSB+; PAS− M4: acute myelomonocytic. ≥30% blasts on nonerythroid series; >20% but <80% monocytic cells; blood monocytes >
/ L; lysozyme >3 × normal. MPO+; NASDA+ M4eo: acute myelomonocytic with eosinophilia. >5% abnormal eosinophils with basophilic granules. MPO+; NASDA+ eosinophils; PAS+ M5a: acute monocytic. >80% of monocytic cells = monoblasts; rest are promonocytes/monocytes. MPO+; NASDA+ M5b: acute monocytic with differentiation. <80% of monocytic cells are monoblasts; rest are promocytes/monocytes. MPO+; NASDA+ M6: acute erythroleukemia. >30% of nonerythroid cells are blasts; >50% of marrow are erythroblasts. PAS+; ringed sideroblasts with iron stain M7: acute megakaryoblastic. >30% of nonerythroid cells are megakaryoblasts; cytoplasmic blebs; myelofibrosis common. MPO−; SBB−; NASDA+ platelet MPO+ by EM EGIL Scoring system for the definition of acute biphenotypic leukemias Scoring lineages points 2: B-lymphoid (CD79a, CD22, cyIgM) T-lymphoid (CD3) myeloid, (MPO) 1: B-lymphoid (CD10, CD19), T-lymphoid (CD2, CD5), myeloid (CD13, CD33) 0.5: B-lymphoid (TdT), T-lymphoid (TdT, CD7), myeloid (CD14, CD15, CD11b, CD11c)
