FAB classification

FAB classification,

(French-American-British) a classification of acute leukemia produced by a three-nation joint collaboration. Acute lymphoblastic leukemia is subdivided into three types and acute myelogenous leukemia is subdivided into eight types.

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FAB classification

French-American-British classification of acute leukemia Hematology A schema that divides acute leukemias into lymphoid–ALL or myeloid–AML cell lines; of childhood ALL, 70% are predominantly L1, 27% are L2, and 3% or less are L3 or Burkitt cell type, in adults with ALL, 30% are L1, 65% are L2, and 5% are L3

FAB classification, acute leukemias

Acute lymphocytic leukemia (ALL)

L1  Small monotonous lymphocytes

L2  Mixed L1- and L3-type lymphocytes

L3  Large homogeneous blast cells

Acute myeloid leukemia (AML)

M1  Myeloblasts without maturation

M2  Myeloblasts with maturation (best AML prognosis)

M3  Hypergranular promyelocytic leukemia (faggot cells)

M3V  Variant, microgranular promyelocytic leukemia

M4  Myelomonocytic leukocytes

M5  Monocytic, subtype

  a. Poorly differentiated monocytic leukemia

  b. Well differentiated monocytic leukemia

M6  Erythroleukemia/DiGuglielmo syndrome

M7  Megakaryocytic leukemia Pleomorphic undifferentiated cells with cytoplasmic blebs; myelofibrosis or ↑ BM reticulin; positive for platelet peroxidase antifactor VIII