A case of therapy-related myeloid neoplasm resulting in acute promyelocytic leukemia in a patient following breast cancer therapy

Abstract

We report a case of therapy-related myeloid neoplasm that resulted in acute promyelocytic leukemia in a patient following therapy for breast cancer. Chromosome analysis did not reveal t(15;17), but fluorescence in situ hybridization and polymerase chain reaction analysis showed a PML/RARA fusion gene, which is a masked t(15;17), demonstrating the importance of genetic analysis. Furthermore, an alkylating agent was used during therapy for breast cancer, and the deletion of the long arm of chromosome 7 was detected, which was previously described for this agent. Generally, in cases of t(15;17), the prognosis for t-MN is good, but in this case, the deletion of the long arm of chromosome 7 resulted in a poor prognosis, suggesting that the evaluation of chromosome abnormalities is essential in the assessment of patients with t-MN.