Cytogenetic Evolution in a Patient with Chronic developing a Secondary Acute Myelogenous Leukemia Subtype M5 Resistant to Imatinib Mesylate Therapy

Abstract

Here we report an unusual case of Chronic Myelogeneous Leukemia (CML) developing towards an Acute Myelogeneous Leukemia subtype M5 (AML-M5). The chromosomal constitution was at (final) stage of AML-M5: Philadelphia chromosome positivity with multiple trisomies, a double t (9; 22) (q34; q11) and an AML1/MDS1/EVI1 (AME) fusion transcript resulting from a t (3; 21) (q26; q22). The latter translocation was detectable first in blast phase of CML and remained present in AML-M5 stage. Overall, four chromosomal analyses were done within 19 months, describing the ongoing karyotypic evolution during this transformation. Unfortunately this exceptional patient did not respond to Imatinib-(IM) or Nilotinib-therapy. These finding May by a first hint that CML-patients acquiring a t (3; 21) (q26; q22) might be appropriate to bone marrow transplantation rather than for IM-therapy.including a double t (9; 22) (q34; q11) and an AME fusion transcript resulting from a t(3;21)(q26;q22).