A Long-Term Survival Case of Acute Myeloid Leukemia With MYC-Positive Double Minute Chromosomes.

Acute myeloid leukemia (AML) with double minute chromosomes (dmin) is a rare complication and has been reported to be refractory to chemotherapy, with a poor prognosis. A 65-year-old woman presented to a local hospital with chronic thyroiditis and sarcoidosis. She underwent a routine blood test that indicated 13% blasts in her peripheral blood. Bone marrow examination revealed 51% myeloblasts with Auer bodies, leading to the diagnosis of AML (French-American-British classification: M2; WHO classification: AML, NOS; AML with maturation). Chromosome examination (G-banding) showed the following karyotypes: 46,XX,2-11 dmin(4/20); 47,idem,+4(5/20); and 46,XX(11/20). Fluorescence in situ hybridization analysis demonstrated amplification of MYC. Genetic testing via leukemia chimeric screening was negative. The patient achieved complete remission (CR) with reduced-dose induction therapy (daunorubicin 50 mg/m² × 3 days; cytarabine 100 mg/m² × 7 days). After three courses of reduced-dose consolidation therapy (high-dose cytarabine 1,500 mg/m²), the patient remained in CR for 5 years and showed long-term survival. AML with amplification of MYC on dmin, combined with complex karyotypes, can acquire resistance to treatment due to the activity of other oncogenes in addition to MYC amplification. In cases with dmin, evaluation of other chromosomes and genetic abnormalities associated with poor prognosis is key to predicting outcome and determining the treatment plan.