Chronic Myeloid Leukemia Progression to Acute Mixed-Lineage Leukemia: a Diagnostic Challenge Complicated by Severe Complications.

Background: Chronic myeloid leukemia (CML) is a myeloproliferative disorder that can progress to an accelerated or blast phase if left untreated or inadequately managed. Acute transformation of CML, particularly into mixed lineage leukemia, is a rare and challenging complication. This case report describes the clinical course of a 30-year-old male patient with CML progressing to acute mixed lineage leukemia and complicated by gastrointestinal bleeding.

Methods: The patient, initially diagnosed with CML in June 2019, was treated with imatinib. However, after discontinuing treatment on his own, the disease progressed to acute myeloid leukemia (AML-M2a) by June 2020, confirmed by bone marrow analysis, flow cytometry, and cytogenetics showing BCR-ABL1 positivity. Despite multiple chemotherapy regimens, including VCLP, VDP with dasatinib, and COP with dasatinib, the patient's condition failed to improve. He developed recurrent gastrointestinal bleeding, which was managed with acid suppression, blood transfusions, and infection control measures.

Results: The patient experienced persistent bone marrow failure, characterized by blasts in peripheral blood and bone marrow, as well as refractory gastrointestinal bleeding despite supportive care. During chemotherapy, the patient also developed severe infections and psychiatric symptoms, complicating the treatment course.

Conclusions: This case highlights the aggressive progression of CML to acute mixed lineage leukemia and underscores the challenges in managing patients with resistant disease. The patient's gastrointestinal bleeding and recurrent infections further complicated treatment, emphasizing the need for early intervention and close monitoring of high-risk CML patients.