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| ==Diagnosis== | | ==Diagnosis== |
| The first clue to a diagnosis of AML is typically an abnormal result on a [[complete blood count]]. While an excess of abnormal white blood cells ([[leukocytosis]]) is a common finding, and leukemic blasts are sometimes seen, AML can also present with isolated decreases in [[platelet]]s, [[red blood cell]]s, or even with a ''low'' white blood cell count ([[leukopenia]]).<ref>Abeloff, Martin et al. (2004), p. 2834.</ref> While a presumptive diagnosis of AML can be made via examination of the peripheral blood smear when there are circulating leukemic blasts, a definitive diagnosis usually requires an adequate bone marrow aspiration and biopsy
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| A [[bone marrow examination]] is often performed to identify the type of abnormal blood cells; however, if there are many leukemic cells circulating in the peripheral blood, a bone marrow [[biopsy]] may not be necessary. Marrow or blood is examined via [[light microscopy]] as well as [[flow cytometry]] to diagnose the presence of leukemia, to differentiate AML from other types of leukemia (e.g. [[acute lymphoblastic leukemia]]), and to classify the subtype of disease (see below). A sample of marrow or blood is typically also tested for [[chromosomal translocation]]s by routine [[cytogenetics]] or [[fluorescent in situ hybridization]].
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| The diagnosis and classification of AML can be challenging, and should be performed by a qualified [[hematopathologist]] or [[hematologist]]. In straightforward cases, the presence of certain morphologic features (such as [[Auer rods]]) or specific flow cytometry results can distinguish AML from other leukemias; however, in the absence of such features, diagnosis may be more difficult.<ref>Abeloff, Martin et al. (2004), p. 2835.</ref>
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| According to the widely used [[WHO]] criteria, the diagnosis of AML is established by demonstrating involvement of more than 20% of the blood and/or bone marrow by leukemic [[myeloblast]]s.<ref>{{cite journal | author = Harris N, Jaffe E, Diebold J, Flandrin G, Muller-Hermelink H, Vardiman J, Lister T, Bloomfield C | title = The World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues. Report of the Clinical Advisory Committee meeting, Airlie House, Virginia, November, 1997 | journal = Ann Oncol | volume = 10 | issue = 12 | pages = 1419–32 | year = 1999 | pmid = 10643532}}</ref> AML must be carefully differentiated from "pre-leukemic" conditions such as [[myelodysplastic syndrome|myelodysplastic]] or [[myeloproliferative syndrome|myeloproliferative]] syndromes, which are treated differently.
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| Because [[acute promyelocytic leukemia]] (APL) has the highest curability and requires a unique form of treatment, it is important to quickly establish or exclude the diagnosis of this subtype of leukemia. [[Fluorescent in situ hybridization]] performed on blood or bone marrow is often used for this purpose, as it readily identifies the [[chromosomal translocation]] (t[15;17]) that characterizes APL.<ref>{{cite journal | author = Grimwade D, Howe K, Langabeer S, Davies L, Oliver F, Walker H, Swirsky D, Wheatley K, Goldstone A, Burnett A, Solomon E | title = Establishing the presence of the t(15;17) in suspected acute promyelocytic leukaemia: cytogenetic, molecular and PML immunofluorescence assessment of patients entered into the M.R.C. ATRA trial. M.R.C. Adult Leukaemia Working Party. | journal = Br J Haematol | volume = 94 | issue = 3 | pages = 557-73 | year = 1996 | pmid = 8790159}}</ref>
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| ===Pathology===
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| <div align="left">
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| <gallery heights="175" widths="175">
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| Image:AML.jpg|AML - Auer Rods, DIC<ref>http://picasaweb.google.com/mcmumbi/USMLEIIImages</ref>
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| Image:AML (with Auer Rods).jpg|AML (with Auer Rods)<ref>http://picasaweb.google.com/mcmumbi/USMLEIIImages</ref>
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| </gallery>
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| </div>
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| ==Classification== | | ==Classification== |