Snapshot A 63-year-old man presents with fever, increasing fatigue, and actively bleeding gums. Physical exam also reveals several oral mucosal petechiae. His CBC reveal decreased platelet and hemoglobin. His PT and PTT are elevated with low fibrinogen. Peripheral blood smear shows blasts and schistocytes. His D-dimer level is elevated. He is diagnosed with DIC and given fresh frozen plasma. He is referred to a hematologist-oncologist. Introduction Acute leukemia resulting in bone marrow failure from neoplastic proliferation Epidemiology median onset 65 years of age Subtypes M3 aka acute promyelocytic leukemia (APL) t(15;17) disruption of retinoic acid receptor (RAR) required for myeloblast maturation associated with DIC presence of Auer rods peroxidase-positive cytoplasmic inclusions acute megakaryoblastic leukemia associated with Down syndrome < 5 years (recall leukemia in Down syndrome occurring in > 5 years = ALL) acute monocytic leukemia infiltration of gums Risk factors alkylating chemotherapy radiation myeloproliferative disorders Down syndrome smoking Presentation Symptoms of pancytopenia (high WBC count but WBCs are dysfunctional) fatigue dyspnea infection due to dysfunctional blasts bleeding Physical exam lymphadenopathy (infiltration of leukemia) hepatosplenomegaly (infiltration of leukemia) fever swollen gums (infiltration of leukemia) Evaluation Best initial test - peripheral blood smear > 20% blasts in blood smear Most accurate test flow cytometry Bone marrow biopsy with cytogenetics myeloblasts with Auer rods in APL myeloperoxidase positive in APL, negative in other subtypes Labs - CBC ↓ RBCs ↓ mature WBCs ↓ platelets Differential Diagnosis ALL Myelodysplastic syndrome CML blast crisis Leukemoid reaction Treatment Initial treatment with chemotherapy to induce remission cytarabine Bone marrow transplant after remission especially for cytogenetics revealing high chance of relapse All-trans-retinoic acid (ATRA) to those with M3 (APL) Prognosis, Prevention, and Complications Prognosis prognostic indicator is cytogenetics 90% complete response rate from initial chemotherapy in those with good cytogenetics relapse rate > 50% with median survival 3-12 months Complications febrile neutropenia DIC (especially with APL) gout tumor lysis syndrome