De novo acute myeloid leukemia harboring concomitant t(8;21)(q22;q22);RUNX1::RUNX1T1 and BCR::ABL1 (p190 minor transcript)

De novo AMLs with typical nonrandom chromosomal abnormalities are often associated with specific morphology subtypes. The t(8;21) is one of the most prominent recurrent cytogenetic aberrations (RCA) in AML, frequently associated with AML with maturation, and is characterized as a good prognostic marker. On the contrary, BCR::ABL1 rearrangement is rarely observed in AMLs, without specific morphology, carrying poor prognosis. Its distinction from blastic transformation of chronic myeloid leukemia has been a matter of long debate. The revised WHO classification (2016) recognized AML with BCR::ABL1(+) as a provisional entity. The occurrence of additional cytogenetic aberrations in AML RCA within the same leukemic clone has been detected, albeit rare cases of BCR::ABL1(+) were reported, mainly as subclones. Those additional cytogenetic and molecular findings seem to significantly affect patient prognosis. Conventional cytogenetic analysis, fluorescent in situ hybridization (FISH), and polymerase chain reaction (PCR) were applied at presentation and during the follow-up of the patient. We present a 34-year-old male patient with de novo AML harboring concomitant t(8;21) and t(9;22) in a single clone. The presence of both t(8;21) and Philadelphia chromosome (Ph+) in the same metaphases but in less than 100% of the analyzed cells, the p190 BCR::ABL transcript type, and absence of splenomegaly support that additional BCR::ABL1(+) is a part of the main leukemic clone. These findings, accompanied with an encouraging outcome of continuous cytogenetic and molecular remission after induction therapy, support BCR::ABL1 being a secondary genetic event in AML with t(8;21).

Automated summary

De novo AML with specific morphology subtypes often have nonrandom chromosomal abnormalities. The t(8;21) is a recurrent cytogenetic aberration frequently associated with AML with maturation and is a good prognostic marker. On the other hand, BCR::ABL1 rearrangement is rarely observed in AMLs without specific morphology and has a poor prognosis. This study presents a case of de novo AML with concomitant t(8;21) and t(9;22), suggesting that BCR::ABL1 may be a secondary genetic event in AML with t(8;21).