Acute myelogenous leukaemia

A life-threatening disorder that predominantly occurs in older adults.

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

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

Cytogenetic abnormalities are prognostically important and affect patient management.

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

It is important to rapidly identify acute promyelocytic leukaemia, 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 leukaemia (AML) is the clonal expansion of myeloid blasts in the bone marrow, peripheral blood, or extramedullary tissues. Bone marrow blasts of at least 20% are diagnostic.[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 presence of 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. AML may arise de novo or secondary to a pre-existing haematological 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

Acute promyelocytic leukaemia (APML) is a form of AML with distinct cytological and clinical features. The classic appearance of APML is a normal WBC count, bi-lobed nuclei, hypergranulated blasts, and bundles of Auer rods.[Figure caption and citation for the preceding image starts]: Peripheral blood film of a patient with acute promyelocytic leukaemia showing hypergranular promyelocytes, some with 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 leukaemia showing hypergranular promyelocytes with bi-lobed nuclei and bundles of Auer rodsFrom the collection of Drs K. Raj and P. Mehta; used with patient consent [Citation ends].