Optimal response to imatinib therapy in a case of chronic myeloid leukemia with a concurrent loss of distal 22q

The hallmark of diagnosing classical chronic myelogenous leukemia (CML) is the identification of Philadelphia (Ph) chromosome (Chr). However, some CML cases show additional structural/numerical chromosomal abnormalities involving either Ph Chr or more frequently other Chrs. Genetic alterations sparing Ph Chr are commonly called “additional chromosomal abnormalities (ACAs)” which have been extensively analyzed in recent large studies. In contrast, the presence of additional genetic abnormalities in Ph Chr has been anecdotally reported with an ambiguity of their impact on treatment response. In our case, we report a newly diagnosed CML patient with the rarest additional chromosomal aberration affecting Ph Chr which has revealed an optimal response over a period of 2 years of follow-up. This report underlines the importance of re-examining CML cases for any ACAs, especially those occurring in Ph Chr, which might be overlooked easily. Moreover, their possible role in disease prognostication should be sought, as well.