ABSTRACT
Acute myeloid leukemia [AML] with t[8;21][q22;q22] generating the AML1/ETO fusion gene on 8q22 is a distinct type of AML t[8;21] category [WHO]/AML-M2 [FAB], generally associated with a favourable prognosis. Variant additional chromosomal abnormalities are frequently reported. We report three adult cases of this category with unusual karyotype. Bone marrow cytogenetics of case no. 1: 45,X,-Y, t[8;21][q13;q22] with a novel breakpoint of chromosome 8 at [q13]. Case no. 2: 46,X,t[X;2][q22;q37],t[3;7][q21;q36],t[5;14][p15;q11],del[8][q22] a complex rearrangement without the involvement of chromosome 21. Case no. 3: 49,XX,+5, t[8;21][q22;q22], +16, +der[21]t[8;21][q22;q22] with additional der[21]. Endometrial in this case which was positive for myeloperoxidase [MPO] and CD117 conforming the AML infiltration. All are morphologically AML with t[8;21]. Relevant literature in cytogenetic of AML-M2 is reviewed. The molecular mechanism involved in unusual rearrangements and clinical significance of them are subjected for further studies