A case report focusing on diagnosis and intervention of chronic myeloid leukemia in blast crisis (acute megakaryoblastic leukemia subtype).

[OBJECTIVES] To report a chronic myeloid leukemia (CML) blast crisis case, accurately diagnose its subtype, explore suitable treatment considering patient factors, and emphasize multidisciplinary diagnosis importance.

[METHODS] Diagnosis relied on multiple approaches: bone marrow morphology, immunophenotyping, chromosomal karyotype analysis, and fusion gene detection to identify the subtype of CML blast crisis. Given the patient's financial constraints and drug availability, the third - generation tyrosine kinase inhibitor (TKI) orelabatinib was chosen for treatment. Minimal residual disease (MRD) was rechecked two weeks after initiating therapy to assess treatment efficacy.

[RESULTS] The patient was diagnosed with CML blast crisis of the acute megakaryoblastic leukemia subtype (M7), presenting with BCR/ABL1 fusion gene positivity, complex karyotypic abnormalities, and secondary myelofibrosis. After two weeks of orelabatinib treatment, MRD levels significantly declined, demonstrating the therapy's effectiveness.

[DISCUSSION] This case underscores the necessity of multidisciplinary collaboration for accurate diagnosis. Treatment selection for rare subtypes like M7 requires balancing medical need with patient - specific factors. The successful reduction in MRD validates the rationality of orelabatinib use, yet more research on treatment options for rare subtypes is warranted.

[CONCLUSION] Multidisciplinary methods are crucial for diagnosing CML blast crisis. Orelabatinib shows efficacy, and more research on personalized treatment is needed.