French-American-British (FAB) classification system

French-A·mer·i·can-Brit·ish (FAB) clas·si·fi·ca·tion sys·tem

(french'ă-mer'i-kăn-brit'ish klas'i-fi-kā'shŭn sis'tĕm) A classification and nomenclature system for acute leukemias based on morphologic characteristics and cytochemical stain reactions. The acute myeloid leukemias are subdivided into eight FAB groups: M0, M1, M2, M3, M4, M5, M6, and M7. The acute lymphoid leukemias are subdivided into three groups: L1, L2, and L3. The myelodysplastic syndromes have also been subdivided by the FAB group into five subgroups: RA, RARS, RAEB, RAEB-T, and CMML.
See also: myelodysplastic syndrome