ETV6-ABL1 fusion is a rare but recurrent genetic aberration found in various hematologic malignancies involving both the lymphoid and myeloid lineage, but to the best of our knowledge, CMML is an exceptionally rare presentation of ETV6-ABL1 rearranged neoplasm.
We screened 45 patients with chronic myelomonocytic leukemia (n = 39 patients, including seven with transformed-acute myeloid leukemia), MDS/MPN unclassifiable (n = 5), and atypical BCR-ABL1-negative CML (n = 1) for mutations in ASXL1, CBL, NRAS, and TET2 genes by molecular genetics including a sensitive next-generation sequencing (NGS) technique.
We investigated 15,542 patients with suspected BCR-ABL1- negative myeloproliferative or myelodysplastic/myeloproliferative neoplasm (including 359 chronic myelomonocytic leukemia) by a molecular marker set.
Although the clinical, morphologic, and laboratory findings vary along a continuum from MDS to MPN, distinctive features are usually present that allow assignment of most of the cases to 1 of 3 distinct subtypes recognized by the 2008 World Health Organization (WHO) classification: chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia, BCR-ABL(-)(aCML, BCR-ABL1(-)), and juvenile myelomonocytic leukemia (JMML).
Five years later, she developed hematologic features of CMML, with t(9;22) translocation, m-BCR rearrangement and high levels of p190 BCR-ABL transcript.