FAB classification


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Related to FAB classification: APML, Auer rods

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.
French-American-British (FAB) classification of acute leukemias: the myeloid leukemias are divided into eight types (M0-7) and the lymphoblastic leukemias into three (L1-3). From Hoffbrand and Pettit, 2000.

FAB classification

French-American-British classification of acute leukemias based on the study of microscopic features and cytochemistry of blast cells; it subdivides acute myelogenous leukemias into 8 groups (M0-M7) and acute lymphoblastic leukemias into 3 groups (L1-L3); widely used in clinical practice.

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
References in periodicals archive ?
Acute myeloid leukaemia FAB classification and its correlation with clinico-heamatological features.
Multivariate analysis of the outcomes in patients who achieved CR and the results of the Cox regression model revealed that, unlike consolidation with high-dose cytarabine (P<0.001), age (P = 0.595), FAB classification (P = 0.092), karyotype (P = 0.116), induction protocol (P = 0.607), and de novo or secondary AML (P = 0.920) were not significantly related to risk of death.
When age, karyotype, FAB classification, induction protocol, and de novo or secondary of AML were constant, the risk of death, was similar in the low-dose and intermediate-high-dose groups compared to the very-high-dose group.
Prognostic importance of morphology (FAB classification) in childhood acute lymphoblastic leukemia (ALL).
In the present study there wasn't a correlation between FLT3 gene mutations, and age, gender, the WBCcount, blast cell rate, or FAB classification. Although it was reported that the FLT3-ITD mutation rate increases with age Meshinchi et al.
FAB classification of acute leukaemia was applied for sub-typing.
Although FAB classification provides a morphological classification of AML, the correlation between morphology and clinical features are imperfect, except in some subtypes of AML (e.g.
(6) In the subsequent revision of the FAB classification in 1985, (7) the criteria for the diagnosis of AML-M6 were refined to include the following: (1) erythroblasts that represent 50% or more of all nucleated bone marrow cells; (2) prominent dyserythropoiesis; (3) and myeloblasts that represent 30% or more of the nonerythroid cells in the bone marrow.
Although the FAB classification has not been formally updated since its 1985 revision, other investigators modified the FAB classification informally by expanding the M6 category to include M6a and M6b subtypes.
This cut-off point is also currently used in under-resourced laboratories in which the FAB classification is more commonly used.