A Rare Case of Chronic Myeloid Leukemia with t(3;9;22) 3-way Translocation

Abstract

Abstract Introduction/Objective Chronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm originating from malignant clonal proliferation of a pluripotent hematopoietic stem cell. CML is characterized by a reciprocal translocation between chromosomes 9 and 22, t(9;22)(q34;q11), that gives rise to an abnormal chromosome 22 called the Philadelphia (Ph) chromosome. The translocation results in the formation of a chimeric BCR-ABL1 fusion gene, which is the molecular hallmark of the disease. However, 5-10% of CML patients present with additional chromosomal abnormalities which is often considered a sign of clonal evolution, genetic instability, and is generally thought to portend a poor prognosis. Methods We present a case of CML with a rare 3- way translocation, t(3;9;22)(q21;q34;q11.2), who achieved a major molecular response on imatinib for 18 months. A review of the literature and Mitelman database search is presented focusing on the prognostic implications of this 3 way translocation in the era of tyrosine kinase inhibitors starting in 2001 till now. Results Twenty seven cases were reported, but the patient therapeutic response to imatinib and clinical outcome were only reported in 11 cases. Nine cases achieved a cytogenetic remission while the remaining two cases had an adverse outcome. Conclusion Taken in conjunction with the favorable outcome in our patient, we suggest that t(3;9;22) is not an adverse prognostic factor in the era of tyrosine kinase inhibitors.