Acute Myeloid Leukemia - AML

Primary Author: Kelley, Todd, MD, MS.

  • Key Points
  • Diagnosis
  • Monitoring
  • Background
  • Lab Tests
  • References
  • Related Topics
  • Videos

Two challenging areas in the evaluation of acute myeloid leukemia (AML) include the diagnosis of acute promyelocytic leukemia (APL) and the prognostication of cytogenetically normal AML (CN-AML).

Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) is a rare subtype of AML that is associated with fatal coagulopathies and hemorrhage. Rapid diagnosis is imperative for reducing morbidity/mortality. APL is readily treatable with all-trans retinoic acid (ATRA), a distinctively different agent from most drugs used in AML. Treatment may be initiated before genetic confirmation is completed; however, genetic confirmation of PML-RARA fusion is mandatory in all cases.

Cytogenetically Normal AML (CN-AML) Prognostic Markers

Cytogenetic analysis is the initial test for risk stratification in acute myeloid leukemia (AML). Fifty percent of patients with AML are cytogenetically normal (CN-AML) and considered to be at intermediate risk, but single gene mutations exist that provide subtype stratification within this risk group. Use of these molecular markers in CN-AML may provide better prognostication and aid in determination of therapeutic regimens. For prognostication purposes, all markers should be interpreted as a group and not individually.

Extracted DNA/RNA can be stored from original specimen and used for additional testing after determination of initial cytogenetic risk classification.

Indications for Testing

  • Anemia, thrombocytopenia, and/or blasts (with or without Auer rods) on peripheral smear

Laboratory Testing

  • Initial testing should include CBC with platelet count and peripheral smear to identify blasts
  • Prothrombin time, partial thromboplastin time and fibrinogen if thrombocytopenia is present (typically promyelocytic leukemias)
    • D-dimer if DIC is suspected

Histology

  • Combination of methods for diagnosis used includes morphology, immunohistochemistry, cytogenetics, and flow cytometric immunophenotyping
    • Key distinction is between AML and acute lymphoblastic leukemia (ALL)
      • AML will demonstrate predominantly myeloid markers and sufficient numbers of lymphoid antigens to raise the possibility of mixed-phenotype acute leukemia
    • Bone marrow biopsy with chromosome analysis
      • Diagnosis of AML requires >20% blasts in peripheral blood or bone marrow unless a recurrent cytogenetic abnormality is present to allow diagnosis in the presence of fewer blasts (eg, CBFB-MYH11)
    • Flow cytometry – establishes myeloid or monocytic lineage
      • Monocytic – CD36, 64, 14, 33+
      • Myeloid – CD13, 15, 33, MPO+
      • Megakaryocytic – CD36+, 41+, 61+
      • Erythroid – CD36, 71+, GlyA+
    • Cytogenetics – provides genetic classification of leukemia; aids in decisions regarding post-inductive therapies
      • Usually assessed using PCR, SNP microarray, next generation sequencing, and/or FISH testing
      • SNP microarray cannot detect t(15;17) (PML-RARA), t(8;21) (RUNX1T1-RUNX1), or balanced rearrangement of MLL or CBFB gene
    • Immunohistochemistry
      • Consider staining for CD19, CD34, CD68, CD79a, CD117, lysozyme, myeloperoxidase, and Pax-5

Prognosis

  • Type of AML
  • Favorable
    • Promyelocytic
    • Megakaryocytic in Down syndrome

Differential Diagnosis

  • Bone marrow biopsy with PCR, FISH, and/or chromosome analysis every 3 months
    • Morphology and immunophenotypic (flow cytometry) bone marrow examination may be done more frequently to assess response to therapy
  • Minimal residual disease (MRD)
    • Chromosome FISH interphase testing – probe detection limit is ~2-5%
    • Depending on clinical setting, flow cytometry or PCR test may be informative
    • Cannot use FISH for PML-RARA due to inadequate sensitivity
    • Immunophenotyping

Acute myeloid leukemia (AML) is a malignant neoplasm of hematopoietic bone marrow precursor cells and is the most common type of acute leukemia in adults. Acute leukemias phenotypically represent immature hematopoietic cells but often display differences from normal cell counterparts.

Epidemiology

  • Incidence
    • Adults – ~3/100,000
    • Children – 0.7/100,000
    • Acute promyelocytic leukemia (APL) – 0.23/100,000
  • Age – more common in elderly; median age of 67 years at diagnosis (NCCN, 2015)
  • Sex – M>F (minimal)

Current Classification

  • Based on blast cytogenetic features, differentiation, and morphology
  • Genetic studies are important in classification and prognosis

Risk Factors

  • Myeloproliferative neoplasm (MPN) or myelodysplastic syndrome (MDS) – chronic myelogenous leukemia, polycythemia vera, essential thrombocythemia, idiopathic myelofibrosis
  • Environmental risk factors – ionizing radiation, benzene, petrochemicals, pesticides
  • Genetic – Down syndromeFanconi anemiaBloom syndrome, Wiskott-Aldrich syndrome, sibling with AML
  • Therapy-related leukemia – previous cytotoxic chemotherapy (alkylating agents, topoisomerase II inhibitors)

Pathophysiology

  • Abnormal proliferation of myeloid precursor cells characterized by
    • Decreased rate of cell self-destruction
    • Arrest of cellular differentiation
  • Leukemic cells have survival advantage
    • Leukemic cells infiltrate bone marrow
    • Blasts and immature cells may populate peripheral blood; however, some patients present with leukopenia

Clinical Presentation

  • Nonspecific symptoms often due to bone marrow infiltration
    • Anemia – weakness, pallor
    • Thrombocytopenia – bruising
  • Leukocytosis with increased peripheral blood blasts
  • Myeloid sarcoma – mass lesion of leukemic cells in tissue
    • Also known as chloroma or extramedullary myeloid tumor
  • Complications

Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Chromosome Analysis, Bone Marrow with Reflex to Genomic Microarray 2007130
Method: Giemsa Band/Genomic Microarray (Oligo-SNP array)

Follow Up

Repeat testing as clinically indicated to monitor disease progression

Leukemia/Lymphoma Phenotyping by Flow Cytometry 2008003
Method: Flow Cytometry

Limitations

Some hematopoietic neoplasms do not show phenotypic abnormalities and therefore may not be detected by flow cytometry

Poor cell viability may adversely affect antigens and impede the ability to properly identify neoplastic cells

Flow results cannot be used alone to diagnose malignancy; should be interpreted in conjunction with morphology, clinical information, and other necessary ancillary tests for a definitive diagnosis

Cytogenomic SNP Microarray - Oncology 2006325
Method: Genomic Microarray (Oligo-SNP Array)

Limitations

Low-level mosaicism (<15% to 20%) may not be detected; test may not be appropriate for individuals with expected lower levels of malignant cells

Does not detect balanced rearrangements; FISH should be used to evaluate specific balanced rearrangements according to indication

Does not detect base pair mutations, and very small deletions/duplications; imbalances of the mitochondrial genome; positional information for chromosome rearrangements, low level clones

Not recommended for MRD

Myeloid Malignancies Somatic Mutation and Copy Number Analysis Panel 2012182
Method: Massively Parallel Sequencing/Genomic Microarray (Oligo-SNP Array)

Limitations

Mutations may be present below the limit of detection

Not intended to detect minimal residual disease (MRD)

Myeloid Malignancies Mutation Panel by Next Generation Sequencing 2011117
Method: Massively Parallel Sequencing

Limitations

Mutations may not be present below the limit of detection

Not intended to detect MRD

Chromosome FISH, Interphase 2002298
Method: Fluorescence in situ Hybridization

Limitations

Limit of detection is probe dependent and ~2-5% in interphase nuclei; residual disease levels lower than this will likely appear normal

Some of these abnormalities can also be detected in myelodysplastic syndrome (MDS) and myeloproliferative neoplasms (MPN) and therefore are not by themselves sufficient for diagnosis but rather consistent with the suspected diagnosis

Follow Up

Repeat testing as clinically indicated to monitor disease progression

Acute Myeloid Leukemia Panel by FISH 2011132
Method: Fluorescence in situ Hybridization

Limitations

Chromosome alterations not targeted by the panel probes will not be detected

Acute Myelogenous Leukemia (AML) with Myelodysplastic Syndrome (MDS) or Therapy-Related AML, by FISH 2002653
Method: Fluorescence in situ Hybridization

Limitations

MLL gene at 11q23 has multiple translocation partners which are not identified by this test

Panel detects only the specific aberrations targeted by the probes

CBFB-MYH11 inv(16) Detection, Quantitative 2011114
Method: Reverse Transcription Quantitative Polymerase Chain Reaction

Limitations

Limit of detection (LOD) for types A, D is one copy

LOD for CBFB-MYH11 type E is 10 copies

Presence of fusion product <10 copies may not be detected

Bone marrow specimens preferred for maximum sensitivity

Poor RNA yield will lead to false negatives

RUNX1-RUNX1T1 (AML1-ETO) t(8;21) Detection, Quantitative 2010138
Method: Quantitative Reverse Transcription Polymerase Chain Reaction

Limitations

“Not Detected” does not exclude the possibility of RUNX1-RUNX1T1 transcripts below the test limit of detection

BM samples preferred for maximum sensitivity

Poor RNA yield and/or quality due to sample age or hypocellularity will negatively impact the test

NPM1 Mutation by PCR and Fragment Analysis 0040174
Method: Polymerase Chain Reaction/Fragment Analysis

Limitations

Negative test result does not exclude presence of mutations in transcripts below the detection limit, presence of rare mutations not detected by this test

All markers should be interpreted as a group and not individually

CEBPA Mutation Detection 2004247
Method: Polymerase Chain Reaction/Sequencing

Limitations

Negative test result does not exclude presence of mutations in transcripts below the detection limit, presence of rare mutations not detected by this test

All markers should be interpreted as a group and not individually

FLT3 Mutation Detection by PCR 2005400
Method: Qualitative Polymerase Chain Reaction/Capillary Electrophoresis

Limitations

Negative test result does not exclude presence of mutations in transcripts below the detection limit, presence of rare mutations not detected by this test

All markers should be interpreted as a group and not individually

FLT3 Signal Ratio Mutation Detection by PCR 2011806
Method: Qualitative Polymerase Chain Reaction/Capillary Electrophoresis

Limitations

Negative test result does not exclude presence of mutations in transcripts below the detection limit, presence of rare mutations not detected by this test

All markers should be interpreted as a group and not individually

IDH1 and IDH2 Mutation Analysis, exon 4 2006444
Method: Polymerase Chain Reaction/Sequencing

Limitations

Negative test result does not exclude mutations below the limit of detection, presence of mutations other than those detected by the test

This marker should be interpreted within the group of CN-AML prognostic markers

WT1 Mutation Detection by Sequencing 2005766
Method: Polymerase Chain Reaction/Sequencing

KIT Mutations in AML by Fragment Analysis and Sequencing 2002437
Method: Polymerase Chain Reaction/Fragment Analysis/Sequencing

Limitations

Not intended to detect minimal residual disease

Mutations outside of exons 8 and 17 are not detected

Mutations below analytical sensitivity will not be detected

Eosinophilia Panel by FISH 2002378
Method: Fluorescence in situ Hybridization

Limitations

Detects only rearrangements targeted by the probes

PDGFRB gene on 5q33 and FGFR1 gene on 8p11 have multiple translocation partners; translocation partners are not identified by this test

CD19 by Immunohistochemistry 2005114
Method: Immunohistochemistry

CD34, QBEnd/10 by Immunohistochemistry 2003556
Method: Immunohistochemistry

CD68, KP1 by Immunohistochemistry 2003598
Method: Immunohistochemistry

CD79A by Immunohistochemistry 2003800
Method: Immunohistochemistry

CD117 (c-Kit) by Immunohistochemistry 2003806
Method: Immunohistochemistry

Myeloperoxidase Stain 0049030
Method: Cytochemical Stain

Pax-5 by Immunohistochemistry 2004082
Method: Immunohistochemistry

Lysozyme (Muramidase) by Immunohistochemistry 2003990
Method: Immunohistochemistry

Esterase, Non-Specific Cytochemical Stain Only 2013277
Method: Cytochemical Stain

Myeloperoxidase, Cytochemical Stain Only 2013273
Method: Cytochemical Stain

Related Tests

Guidelines

Cheson BD, Bennett JM, Kopecky KJ, Büchner T, Willman CL, Estey EH, Schiffer CA, Doehner H, Tallman MS, Lister A, Lo-Coco F, Willemze R, Biondi A, Hiddemann W, Larson RA, Lowenberg B, Sanz MA, Head DR, Ohno R, Bloomfield CD, LoCocco F, International Working Group for Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and Reporting Standards for Therapeutic Trials in Acute Myeloid Leukemia. Revised recommendations of the International Working Group for Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and Reporting Standards for Therapeutic Trials in Acute Myeloid Leukemia. J Clin Oncol. 2003; 21(24): 4642-9. PubMed

Döhner H, Estey EH, Amadori S, Appelbaum FR, Büchner T, Burnett AK, Dombret H, Fenaux P, Grimwade D, Larson RA, Lo-Coco F, Naoe T, Niederwieser D, Ossenkoppele GJ, Sanz MA, Sierra J, Tallman MS, Lowenberg B, Bloomfield CD, European LeukemiaNet. Diagnosis and management of acute myeloid leukemia in adults: recommendations from an international expert panel, on behalf of the European LeukemiaNet. Blood. 2010; 115(3): 453-74. PubMed

NCCN Clinical Practice Guidelines in Oncology, Acute Myeloid Leukemia. National Comprehensive Cancer Network. Fort Washington, PA [Accessed: Jun 2015]

General References

Döhner H, Gaidzik VI. Impact of genetic features on treatment decisions in AML. Hematology Am Soc Hematol Educ Program. 2011; 2011: 36-42. PubMed

Döhner H, Weisdorf DJ, Bloomfield CD. Acute Myeloid Leukemia. N Engl J Med. 2015; 373(12): 1136-52. PubMed

Jabbour EJ, Estey E, Kantarjian HM. Adult acute myeloid leukemia. Mayo Clin Proc. 2006; 81(2): 247-60. PubMed

Lin TL, Smith D. Prognostically important molecular markers in cytogenetically normal acute myeloid leukemia. Am J Med Sci. 2011; 341(5): 404-8. PubMed

Morrissette JJ D, Bagg A. Acute myeloid leukemia: conventional cytogenetics, FISH, and moleculocentric methodologies. Clin Lab Med. 2011; 31(4): 659-86, x. PubMed

Sanz MA, Grimwade D, Tallman MS, Lowenberg B, Fenaux P, Estey EH, Naoe T, Lengfelder E, Büchner T, Döhner H, Burnett AK, Lo-Coco F. Management of acute promyelocytic leukemia: recommendations from an expert panel on behalf of the European LeukemiaNet. Blood. 2009; 113(9): 1875-91. PubMed

Schoch C. M3/M3v acute myeloid leukemia (AML M3/M3v); Acute promyelocytic leukemia (APL). Atlas of Genetics and Cytogenetics in Oncology and Haematology. Poitiers, France [Accessed: Nov 2015]

Sun T. Clinical Application: Case 6.. In Pine J, McGough J, et al, eds. Flow Cytometry and Immunohistochemistry for Hematologic Neoplasms, 2nd ed.. Philadelphia, PA: Lippincott Williams & Wilkins, 2011.

Swerdlow S, Campo E, Harris N, Jaffe E, Pileri S, Harald S, Thiele J, Vardiman J. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, 4th ed. Lyon, France: International Agency for Research on Cancer, 2008.

Watt CD, Bagg A. Molecular diagnosis of acute myeloid leukemia. Expert Rev Mol Diagn. 2010; 10(8): 993-1012. PubMed

Zhou Y, Jorgensen JL, Wang SA, Ravandi F, Cortes J, Kantarjian HM, Medeiros J, Konoplev S. Usefulness of CD11a and CD18 in flow cytometric immunophenotypic analysis for diagnosis of acute promyelocytic leukemia. Am J Clin Pathol. 2012; 138(5): 744-50. PubMed

Ziai JM, Siddon AJ, Education Committee of the Academy of Clinical Laboratory Physicians and Scientists. Pathology Consultation on Gene Mutations in Acute Myeloid Leukemia. Am J Clin Pathol. 2015; 144(4): 539-54. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Chen Z, Pasquini M, Hong B, DeHart S, Heikens M, Tsai S. The human Penumbra gene is mapped to a region on chromosome 7 frequently deleted in myeloid malignancies. Cancer Genet Cytogenet. 2005; 162(2): 95-8. PubMed

Koshy J, Qian Y, Bhagwath G, Willis M, Kelley TW, Papenhausen P. Microarray, gene sequencing, and reverse transcriptase-polymerase chain reaction analyses of a cryptic PML-RARA translocation. Cancer Genet. 2012; 205(10): 537-40. PubMed

Liew M, Mao R, Wittwer CT, Salama ME. Detection of chromosomal translocations in formalin-fixed paraffin-embedded (FFPE) leukemic specimens by digital expression profiling Int J Lab Hematol. 2015; 37(5): 690-8. PubMed

Matynia AP, Szankasi P, Shen W, Kelley TW. Molecular genetic biomarkers in myeloid malignancies Arch Pathol Lab Med. 2015; 139(5): 594-601. PubMed

Prchal JT. Molecular basis of polycythemic disorders due to aberrant hypoxia sensing and its relevance to acute leukemia. Best Pract Res Clin Haematol. 2012; 25(4): 493-7. PubMed

Ridges S, Heaton WL, Joshi D, Choi H, Eiring A, Batchelor L, Choudhry P, Manos EJ, Sofla H, Sanati A, Welborn S, Agarwal A, Spangrude GJ, Miles RR, Cox JE, Frazer K, Deininger M, Balan K, Sigman M, Müschen M, Perova T, Johnson R, Montpellier B, Guidos CJ, Jones DA, Trede NS. Zebrafish screen identifies novel compound with selective toxicity against leukemia. Blood. 2012; 119(24): 5621-31. PubMed

Schumacher JA, Reading S, Szankasi P, Matynia AP, Kelley TW. A novel approach to quantitating leukemia fusion transcripts by qRT-PCR without the need for standard curves Exp Mol Pathol. 2015; 99(1): 104-8. PubMed

Spencer DH, Abel HJ, Lockwood CM, Payton JE, Szankasi P, Kelley TW, Kulkarni S, Pfeifer JD, Duncavage EJ. Detection of FLT3 internal tandem duplication in targeted, short-read-length, next-generation sequencing data. J Mol Diagn. 2013; 15(1): 81-93. PubMed

Talpaz M, Paquette R, Afrin L, Hamburg SI, Prchal JT, Jamieson K, Terebelo HR, Ortega GL, Lyons RM, Tiu RV, Winton EF, Natrajan K, Odenike O, Claxton D, Peng W, O'Neill P, Erickson-Viitanen S, Leopold L, Sandor V, Levy RS, Kantarjian HM, Verstovsek S. Interim analysis of safety and efficacy of ruxolitinib in patients with myelofibrosis and low platelet counts. J Hematol Oncol. 2013; 6(1): 81. PubMed

Tomasic NLjubas, Piterkova L, Huff C, Bilic E, Yoon D, Miasnikova GY, Sergueeva AI, Niu X, Nekhai S, Gordeuk V, Prchal JT. The phenotype of polycythemia due to Croatian homozygous VHL (571C>G:H191D) mutation is different from that of Chuvash polycythemia (VHL 598C>T:R200W). Haematologica. 2013; 98(4): 560-7. PubMed

Yang DT, Greenwood JH, Hartung L, Hill S, Perkins SL, Bahler DW. Flow cytometric analysis of different CD14 epitopes can help identify immature monocytic populations. Am J Clin Pathol. 2005; 124(6): 930-6. PubMed

Medical Reviewers

Last Update: July 2016