Hematopathological Patterns in Acute Myeloid Leukemia with Complications of Overt Disseminated Intravascular...

Background: Acute myeloid leukemia (AML) complicated by disseminated intravascular coagulation (DIC) poses major diagnostic and therapeutic challenges. While DIC is well documented in acute promyelocytic leukemia, its manifestations in non-APL AML remain underexplored, necessitating precise diagnostic strategies for effective management. Methods: AML patients with overt DIC were analyzed, including morphological, immunophenotypic, cytogenetic, and genetic evaluations. DIC was diagnosed using the ISTH scoring system, and AML subtypes were classified following WHO criteria. Results: Three diagnostic patterns were identified. (1) Acute promyelocytic leukemia: Leukemia characterized by PML::RARa rearrangements, FLT3 co-mutations, and frequent Auer rods and faggot bundles. Immunocytological analysis showed CD34 and HLA-DR negativity. (2) AML with FLT3 and/or NPM1 mutations: A high prevalence of cup-like blasts was found in 70% of cases. FLT3 mutations, often co-occurring with NPM1, dominated, while karyotypes were typically normal. Immunophenotyping revealed strong myeloid marker expression (MPO+, CD13+, and CD33+), with occasional CD34 negativity. (3) AML with monocytic differentiation: Leukemia defined by monoblastic/promonocytic morphology, DNMT3A mutations, and complex karyotypes or 11q23 rearrangements. Immunophenotyping demonstrated a dominance of monocytic markers (CD4+, CD14+, CD15+, and CD64+). Two patients presented unique profiles with no alignment to these patterns. Conclusions: This study highlights distinct hematopathological patterns of AML with overt DIC, providing a framework for early and precise diagnosis. Recognizing these patterns is critical for tailoring diagnostic and therapeutic approaches to improve outcomes in this high-risk population.