Acute myeloid leukemia

Acute myeloid leukemia (AML) is a life-threatening hematologic malignancy that predominantly occurs in older adults.

Many subtypes exist, of which acute promyelocytic leukemia merits specific management.

Characteristically abnormal blasts are present in the peripheral blood, and normal hematopoiesis is reduced. Definitive diagnosis requires bone marrow biopsy. Presence of ≥20% blast cells in the peripheral blood and/or bone marrow confirms the diagnosis.

Cytogenetic, genetic, and epigenetic abnormalities are prognostically important and affect patient management.

Most patients are treated with chemotherapy induction, consolidation, and maintenance regimens. Hematopoietic stem cell transplantation may also be used in select patients.

It is important to rapidly identify acute promyelocytic leukemia, as associated coagulopathy may be life threatening.

Although most patients achieve complete remission, a high incidence of relapse leads to poor overall survival.

Acute myeloid leukemia (AML) is a life-threatening hematologic malignancy caused by clonal expansion of myeloid blasts in the bone marrow, peripheral blood, or extramedullary tissues. The presence of ≥20% blast cells in the bone marrow or peripheral blood confirms the diagnosis.[1]Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016 May 19;127(20):2391-405. http://www.bloodjournal.org/content/127/20/2391.long?sso-checked=true http://www.ncbi.nlm.nih.gov/pubmed/27069254?tool=bestpractice.com Specific clonal cytogenetic abnormalities, such as t(8;21)(q22;q22), inv(16)(p13;q22), t(16;16)(p13;q22), and t(15;17)(q22;q12), also define AML irrespective of the blast count.[1]Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016 May 19;127(20):2391-405. http://www.bloodjournal.org/content/127/20/2391.long?sso-checked=true http://www.ncbi.nlm.nih.gov/pubmed/27069254?tool=bestpractice.com [2]Döhner H, Estey E, Grimwade D, et al. Diagnosis and management of AML in adults: 2017 ELN recommendations from an international expert panel. Blood. 2017 Jan 26;129(4):424-47. https://ashpublications.org/blood/article/129/4/424/36196/Diagnosis-and-management-of-AML-in-adults-2017-ELN http://www.ncbi.nlm.nih.gov/pubmed/27895058?tool=bestpractice.com AML may arise de novo or secondary to a preexisting hematologic disorder, such as myelodysplastic syndrome.[1]Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016 May 19;127(20):2391-405. http://www.bloodjournal.org/content/127/20/2391.long?sso-checked=true http://www.ncbi.nlm.nih.gov/pubmed/27069254?tool=bestpractice.com

The acute promyelocytic leukemia (APML) subtype of AML is characterized by a distinctive cytomorphology (hypergranular promyelocytes with bilobed nuclei and bundles of Auer rods), a tendency for coagulopathy (due to thrombocytopenia and fibrinolysis), and a specific t(15;17) translocation resulting in a novel PML/RAR-alpha fusion gene. [Figure caption and citation for the preceding image starts]: Peripheral blood film of a patient with acute promyelocytic leukemia showing hypergranular promyelocytes with bilobed nuclei and bundles of Auer rodsFrom the collection of Drs K. Raj and P. Mehta; used with patient consent [Citation ends].[Figure caption and citation for the preceding image starts]: Peripheral blood film of a patient with acute promyelocytic leukemia showing hypergranular promyelocytes, some with bundles of Auer rodsFrom the collection of Drs K. Raj and P. Mehta; used with patient consent [Citation ends].