Further study on FAB-E [Egyptian modification of FAB classification] concerning acute myeloid and monocytic leukemia

ABSTRACT

In a previous work, Egyptian modification of FAB [FAB-E] was proposed in which cases with mixed criteria between L1 and L2 were simply classified as L1 and L2 subtype and the same for L2-L3 subtype. They were found to hold midway positions as regards prognosis between L1 and L2 in the first and L2 and L3 in the second. This work is extended to include acute myeloid and monocytic leukemias. A total of 173 cases of AML [98 adults and 75 children] were classified on morphologic basis into M1 with the vast majority of cells pure non- granulated primitive myeloblasts [9 adults and 6 children], M2a with the vast majority of cells are mixed myeloblasts and leukoblasts [42 adults and 22 children], and M2b with mixed blasts and promyelocytes [47 adults and 47 children]. The prognosis showed better remissions and response as it goes from M1 to M2a, to M2b. Thirty cases [19 adults and 11 children] of monocytic leukemia were also studied and subdivided into M5a with primitive monoblasts, mostly undifferentiated, with little promonocytes and monocytes if any [5 adult and 3 children], M5b with mixed monoblasts and promonocytes; over 30% and the rest mature monocytes [11 adults and 5 children], and M5c with the majority mature monocytes and few monoblasts and/or promonocytes [3 adults and 3 children]. As regards prognosis it was found to be worst in M5a, less worse in M5b, and least worse in M5c