Acute Promyelocytic Leukemia: Pathophysiology, Diagnosis and Clinical Management

<b>Background/Objectives</b>: Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia characterized by the t(15;17)(q24;q21) translocation, generating the <i>PML::RARA</i> fusion gene that blocks myeloid differentiation and drives leukemogenesis. Despite advances in therapy, early mortality remains a major challenge due to severe coagulopathy. This review aims to summarize recent insights into APL pathophysiology, diagnostic approaches, and management strategies. <b>Methods:</b> We performed a comprehensive review of the literature addressing the molecular mechanisms of APL, its associated coagulopathy, and current diagnostic and therapeutic standards, with a focus on evidence-based recommendations for clinical practice. <b>Results:</b> The hallmark PML: RARA oncoprotein disrupts nuclear body function and retinoic acid signaling, resulting in differentiation arrest and apoptosis resistance. APL-associated coagulopathy arises from overexpression of tissue factor, release of cancer procoagulant, inflammatory cytokines, and annexin II-mediated hyperfibrinolysis. Diagnosis requires integration of cytomorphology, immunophenotyping, coagulation studies, and molecular confirmation. Immediate initiation of all-trans-retinoic acid (ATRA) upon clinical suspicion, combined with aggressive supportive care, is critical to control bleeding risk. <b>Conclusions:</b> APL is now a highly curable leukemia when recognized early and treated with targeted therapy. Rapid diagnosis, prompt ATRA administration, and meticulous hemostatic support are essential to reduce early mortality. Further refinements in minimal residual disease monitoring are expected to improve patient outcomes.