Precursor B-Cell Acute Lymphoblastic Leukemia in Two Patients with a History of Cytotoxic Therapy / 대한내과학회지

Therapy-related myeloid neoplasms have been well characterized. However, precursor B-cell acute lymphoblastic leukemia in patients with prior malignancies is uncommon, and the effect of prior cytotoxic therapy on development of precursor B-cell acute lymphoblastic leukemia is controversial. Therapy-related precursor B-cell acute lymphoblastic leukemia has been reported occasionally. However, cytotoxic therapy-related precursor B-cell acute lymphoblastic leukemia has been reported in Korea only rarely. We herein describe two cases of therapy-related precursor B-cell acute lymphoblastic leukemia.

MYC Rearrangement Involving a Novel Non-immunoglobulin Chromosomal Locus in Precursor B-cell Acute Lymphoblastic Leukemia

MYC rearrangement, a characteristic cytogenetic abnormality of Burkitt lymphoma and several subsets of other mature B-cell neoplasms, typically involves an immunoglobulin gene partner. Herein, we describe a case of precursor B-cell lymphoblastic leukemia harboring a MYC rearrangement with a novel non-immunoglobulin partner locus. The patient was a 4-yr-old Korean boy with ALL of the precursor B-cell immunophenotype. At the time of the second relapse, cytogenetic analyses revealed t(4;8)(q31.1;q24.1) as a clonal evolution. The MYC rearrangement was confirmed by FISH analysis. He died 3 months after the second relapse without achieving complete remission. To our knowledge, this is the first report of a case of MYC rearrangement with a non-immunoglobulin partner in precursor B-cell lymphoblastic leukemia.