Acute Myeloid Leukemia - AML

Key Points

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 hemorrhages. Rapid diagnosis is imperative to reduce 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 the PML-RARA fusion is mandatory in all cases.

Clinical Findings
  • Bleeding, bruising, pallor (due to cytopenias that may be profound)
    • Combination of symptoms is common
  • Life threatening coagulopathies (DIC) may occur
  • Bleeding secondary to DIC – unique to APL
Morphology
  • Presence of atypical promyelocytes in peripheral blood and bone marrow
  • Peripheral blood
    • Circulating blasts may be few in number
    • Thrombocytopenia – often severe
    • 2 morphological variants
      • Microgranular variant – more likely associated with leukocytosis
      • Hypergranular variant – more likely associated with leukopenia
  • Bone marrow 
    • Blasts (atypical promyelocytes) are myeloperoxidase (strong, uniform) positive
    • Significant infiltration with atypical promyelocytes
      • Hypergranular variant – often multiple Auer rods in a single cell
      • Microgranular variant – bilobed, reniform, or monocyte-like nuclei
Immunophenotype (flow cytometry)
  • Atypical promyelocytes of APL generally express CD33 and CD117 without CD34 or HLA-DR and have slightly higher side scatter characteristics than normal myeloblasts
  • Microgranular variant may also show aberrant expression of CD2
  • Immunophenotypic features
    • Myelomonocytic antigens
      • Positive – CD13, CD33
      • Negative – CD14
    • Granulocyte differentiation markers
      • Negative or weakly expressed – CD15,  CD65
      • Positive – CD64
    • Leukocyte integrin markers
      • Low or absent – CD11a, CD11b, CD11c
      • Positive – CD33, CD64, CD117
Molecular Biology
  • APL with t(15;17)(q24.1;q21.1) – PML-RARA
    • Reciprocal translocation between the long arms of chromosomes 15 and 17 with the creation of a fusion gene (PML-RARA) that links the retinoic acid receptor alpha (RARA) gene on chromosome 17 with the PML gene on chromosome 15  
  • Chromosomal banding
    • Variable breakpoints reported – t(15;17)(q24;q21); t(15;17)(q22;q12)
    • Rarely t(5;17) or t(11;17), indicating RARA with alternative partners
Laboratory Tests for Genetic Confirmation of the PML-RARA Fusion

Laboratory Tests for Genetic Confirmation of the PML-RARA Fusion

Fluorescence in situ hybridization

Highly efficient for confirming APL

ARUP Tests

PML-RARA Translocation by FISH 2002363

Acute Myelogenous Leukemia Panel by FISH 2002384

Test Characteristics

  • Probes designed to check fusion of PML and RARA
  • Bone marrow preferred; however, peripheral blood may be used when hyperleukocytosis is present

Advantages

  • Results usually available within 24 hrs
  • High sensitivity, specificity
  • Less expensive and time-consuming than karyotyping
  • Can raise suspicion of rare subtypes of APL (eg, t(11;17), t(5;17))

Disadvantages

  • May take up to 2 days for results
  • False negatives –  cryptic rearrangements may be missed that lead to PML-RARA fusion
    • Variant translocation involving gene partners other than PML may be missed
    • Does not provide the sensitivity required for monitoring minimal residual disease (MRD)

Molecular Studies (Reverse Transcriptase-PCR)

Allows for accurate quantitation of PML-RARA for monitoring response to therapy

ARUP Test

PML-RARA Translocation, t(15;17) by RT-PCR, Quantitative 2002871

Test Characteristics

  • Detects all 3 PML-RARA fusion types (long, short, and variable forms)

Advantages

  • Highly sensitive, specific, and quantitative
  • Most useful post consolidation therapy monitoring

Disadvantages

  • False negatives – due to poor RNA yield
  • May require more time than FISH testing
  • Translocations involving other gene partners will not be detected

Cytogenetic (Conventional Karyotyping)

ARUP Test

Chromosome Analysis, Bone Marrow 2002292

Test Characteristics

  • Uses G-banded metaphases from bone marrow culture
  • Translocations (fusions)
    • Classic translocation
      •  t(15;17)(q22;q21) – PML-RARA
    • Less common translocations
      • t(11;17)(q23;21) – PLZF-RARA
      • t(11;17)(q13;21) – NuMA-RARA
      • t(5;17)(q35;21) – NPM1-RARA

Advantages

  • Highly specific
  • Can characterize cases lacking the PML-RARA fusion
  • Can detect rare subtypes of APL (eg, t(11;17), t(5;17))

Disadvantages

  • Requires up to 10 days for results
  • Requires good quality metaphases
  • False negatives – cryptic rearrangements (PML-RARA fusion will be missed)
Sanz, M 2009; Sun T, 2008; Swerdlow  SH et al 2008; Zhou Y, 2012 Atlas of Genetic and Cytogenetics in Oncology 11-14-12

Cytogenetically-Normal AML (CN-AML) Prognostic Markers

Cytogenetic analysis is the initial test for risk stratification in acute myeloid leukemia (AML). Although 50% of AML cases are cytogenetically normal (CN-AML) and considered to be intermediate risk, single gene mutations exist that provide subtype stratification within this risk group. Use of these new 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 samples and used for additional testing after determination of initial cytogenetic risk classification.

Molecular Markers in CN-AML
Molecular Markers in CN-AML

Marker

Biology

Prognosis

Well-Characterized Markers

NPM1 mutation

ARUP Test

Whole blood or bone marrow

Nucleolar phosphoprotein that shuttles between nucleus and cytoplasm

NPM1 mutations associated with favorable outcome

CEBPA mutations

ARUP Test

Whole blood or bone marrow

Transcription factor involved in myeloid differentiation

Double CEBPA mutations associated with favorable outcome

Single CEBPA mutations have unclear clinical significance

FLT3 mutations

ARUP Test

Whole blood or bone marrow

Tyrosine kinase receptor expressed by hematopoietic progenitor cells that regulate cell survival and maturation

FLT3 internal tandem mutations (ITD) associated with unfavorable outcome

FLT3 D385 (tyrosine kinase domain mutations) associated with unfavorable outcome

Investigational Markers

IDH1 mutation, IDH2 mutation

ARUP Test

Whole blood or bone marrow

Enzyme involved in citric acid cycle

Mutations cause neomorphic activity that leads to production of the onco metabolite 2-hydroxyglutarate

IDH1 SNP rs11554137 associated with unfavorable outcome, particularly with FLT3 or NPM1 wild type mutations

WT1 mutation

ARUP Test

Whole blood or bone marrow  

Transcription factor expressed in embryonic kidney cells and hematopoietic cells that has both tumor suppressor and oncogenic functions

Mutations of exon 7 or 9 associated with unfavorable outcome

G-allele of SNP rs16754 in exon 7 associated with improved outcome in patients with FLT3 and wild-type NPM1 mutations in the absence of FLT3 mutations

DNMT3A mutation

Encodes for methyltransferases

Mutations cause reduced enzymatic activity with aberrant DNA methylation

DNMT3A mutation associated with unfavorable outcome

BAALC overexpression

Expressed in CD34-positive hemopoietic progenitors and neural tissue; functions in cytoskeleton

Overexpression associated with unfavorable outcome

MLL partial tandem duplication (PTD) mutations, overexpression

Involved in chromatin modification

MLL PTD associated with less favorable outcome

BAALC – brain and acute leukemia, cytoplasmic; CEBPA – CAAT/enhancer binding protein (C/EBP) α; DNMT3A – DNA (cytosine-5-)-methyltransferase 3 alpha; FLT3 – FMS-related tyrosine kinase 3; IDH1 – isocitrate dehydrogenase 1 (NADP+), soluble; IDH2 – isocitrate dehydrogenase 2 (NADP+), mitochondrial; MLL – myeloid/lymphoid or mixed-lineage leukemia; NPM1 – nucleophosmin (nucleolar phosphoprotein B23, numatrin); WT1 – Wilms tumor 1

Dohner, H, 2011; Lin et al, 2011; Watt et al, 2010.

Diagnosis

Indications for Testing

  • Findings of 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 present (typically promyelocytic leukemias)
    • D-dimer if DIC is suspected

Histology

  • Combination of methods used include morphology, immunohistochemistry, cytogenetics, and flow cytometric immunophenotyping
    • Key distinction is between AML and acute lymphoblastic leukemia (ALL)
      • AML will demonstrate mostly myeloid markers without expressing 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 with 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 as well as decisions about post-inductive therapies
      • Usually assessed using PCR, SNP microarray, and/or FISH testing
      • SNP microarray cannot detect t(15;17) (PML-RARA), t(8;21) (RUNX1T1-RUNX1), or balanced rearrangement of MLL or CBFβ gene
      • FISH probes for AML (these mutations are difficult to detect by classical cytogenetics)
        • PML-RARA t(15;17) – identifies APL
        • RUNX1-RUNX1T1 t(8;21) – identifies core binding factor-related (CBF) AML
        • CBFB-MYH11 inv(16)/t(16;16) – identifies CBF AML
        • MLL 11q23 rearrangements
    • Immunohistochemistry
      • Most useful stains include CD19, CD34, CD68, CD79a, CD117, lysozyme, myeloperoxidase, and Pax-5
    • Molecular testing for KIT mutations for inv(16) or t(8;21) AML 
      • Presence of KIT mutation affects outcomes

Prognosis

  • Dependent on karyotyping, type of AML, and cytogenetic results
  • Karyotyping
    • Favorable 
      • t(8,21) – RUNX1-RUNX1T1
      • inv(16) – CBFB-MYH11
      • t(15;17) – PML-RARA
      • t(1;11) (q21;q23) – MLL 11q23
    • Intermediate
      • Normal karyotype
      • Diploid
      • +8
      • del(12p)
      • +6
      • -Y
      • t(9;11) – MLL-AF4, 11q23
    • Unfavorable
      • Non t(9;11)11q23 rearrangements
      • t(9;22) BCR-ABL1 [Philadelphia+ (Ph+)]
      • -5/del(5q)
      • -7/del(7q)
      • Abnormal 3q, 9q, 11q, 20q, 21q, 17p
      • t(6;9) – DEK-CAN
      • t(6:11) (q27;q23) – MLLT4
      • t(10;11) (p12;q23) – MLLT10
      • inv(3) or t(3;3) – EVI1
      • Complex karyotypes – ≥3 clonal abnormalities
  • Type of AML
    • Favorable
      • Promyelocytic
      • Megakaryocytic in Down syndrome

Differential Diagnosis

Monitoring

  • Bone marrow biopsy with PCR, FISH, 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
  • Response criteria for AML

    Response Criteria for AML*

    Morphologic leukemia-free state

    • Bone marrow <5% blasts in aspirate with spicules
    • No blasts with Auer rods or persistence of extramedullary disease
    • Question of residual leukemia
      • Repeat bone marrow aspirate/biopsy in one week
      • Perform bone marrow biopsy if no spicules found in aspirate sample

    Complete remission (CR)

    • Morphologic CR – patient independent of transfusions
      • Absolute neutrophil count >1,000/mcL
      • Platelets ≥100,000/mcL
      • No evidence of residual extramedullary disease
    • Cytogenetic CR – cytogenetics normal (in those with previously abnormal cytogenetics)
    • Molecular CR – molecular studies negative (for promyelocytic and Ph+ only)

    Partial remission (useful only in Phase I trials and not as a goal for standard therapy)

    • Decrease of ≥50% in percentage of blasts in bone marrow aspirate
    • Normalization of blood counts, as noted in morphologic CR

    No remission

    • Patient fails to achieve complete response – considered treatment failure

    Relapse following complete response

    • Defined as reappearance of leukemic blasts in peripheral blood or finding of >5% blasts in bone marrow not attributable to another cause (eg, bone marrow regeneration after consolidation therapy) or extramedullary relapse

    *Adapted from 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, 2003

Clinical Background

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 per year
    • Children – 0.7/100,000 per year
  • Age – more common in elderly; median age of 67 years at diagnosis
  • Sex – M>F (minimal)

Current Classification

  • Based on blast cytogenetic features, differentiation, and morphology
  • Genetic studies are important in classification and prognosis
  • WHO classification of acute myeloid leukemia – based on genetics and morphology
    WHO Classification of Acute Myeloid Leukemia (2008)*

    Acute myeloid leukemia with recurrent genetic abnormalities

    • Acute myeloid leukemia with t(8;21)(q22;q22), (AML1-ETO)
    • Acute myeloid leukemia with abnormal bone marrow eosinophils and inv(16)(p13q22) or t(16;16)(p13;q22), (CBFB-MYH11)
    • Acute promyelocytic leukemia with t(15;17)(q22;q12), (PML-RARA) and variants (M3)
    • Acute myeloid leukemia with 11q23 (MLL) abnormalities

    Acute myeloid leukemia with multilineage dysplasia

    Acute myeloid leukemia and myelodysplastic syndromes, therapy related

    • Alkylating agent/radiation-related type
    • Topoisomerase II inhibitor-related type (some may be lymphoid)
    • Others

    Acute myeloid leukemia, not otherwise categorized

    • Acute myeloid leukemia, minimally differentiated (M0)
    • Acute myeloid leukemia without maturation (M1)
    • Acute myeloid leukemia with maturation (M2)
    • Acute myelomonocytic leukemia (M4)
    • Acute monoblastic (M5a)/acute monocytic leukemia (M5b)
    • Acute erythroid leukemia (erythroid/myeloid and pure erythroleukemia) (M6)
    • Acute megakaryoblastic leukemia (M7)
    • Acute basophilic leukemia
    • Acute panmyelosis with myelofibrosis
    • Myeloid sarcoma
    *Defined as ≥20% blasts in blood or bone marrow; however, clonal, recurring cytogenetic abnormalities should be considered AML regardless of blast percentage. Ongoing clinical trials may continue to use French-American-British (FAB) criteria of ≥30% blasts until completion of trial. FAB classification identified as M0 through M7.

Risk Factors

  • Myeloproliferative neoplasm (MPN) or myelodysplastic syndrome (MDS) – chronic myelogenous leukemia, polycythemia vera, essential thrombocythemia, idiopathic myelofibrosis
  • Environmental risk factors – radiation, benzene, paint, pesticides
  • Genetic – Down syndrome, Fanconi anemia, Bloom syndrome, Wiskott-Aldrich syndrome, sibling with AML
  • Drugs – cytotoxic chemotherapy (eg, 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 such as weakness, fever, bruising, weight loss
  • Leukocytosis with increased peripheral blood blasts
  • Thrombocytopenia, anemia
  • Myeloid sarcoma – mass lesion of leukemic cells in tissue
    • Also known as chloroma or extramedullary myeloid tumor
  • Complications

Indications for Laboratory Testing

  • 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
Test Name and Number Recommended Use Limitations Follow Up
Chromosome Analysis, Bone Marrow with Reflex to Genomic Microarray 2007130
Method: Giemsa Band/Genomic Microarray (Oligo-SNP array)

Detect chromosome abnormalities in bone marrow aspirate consistent with the diagnosis of AML, some of which also have classification and prognostic significance

Reflex pattern - if chromosome analysis is "normal" or "no growth," then genomic microarray testing will be added

 

Repeat testing as clinically indicated to monitor disease progression

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

Aid in evaluation of hematopoietic neoplasms (ie, leukemia, lymphoma)

Monitor therapy in patients with established diagnosis of hematopoietic neoplasms

Specimens include peripheral blood, bone marrow, and tissue

Markers selected based on clinical history, previous flow studies, and pathologist interpretation

Available markers:

Myelo/Mono: CD11b, CD13, CD14 (Mo2), CD14 (MY4), CD15, CD33, CD64, CD117, myeloperoxidase

T cell: CD1, CD2, CD3, CD4, CD5, CD7, CD8, TCR alpha-beta, TCR gamma-delta, cytoplasmic CD3

B cell: CD10, CD19, CD20, CD22, CD23, CD103, kappa, lambda, FMC7, cytoplasmic kappa, cytoplasmic lambda

Misc: CD11c, CD16, CD25, CD30, CD34, CD38, CD41, CD42b, CD45, CD56, CD57, CD61, HLA-DR, glycophorin, TdT, bcl-2, ALK-1, CD123, CD138, CD200, CD26, CD45

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

Preferred test at time of diagnosis to detect prognostically important genomic abnormalities (loss/gain of DNA and/or loss of heterozygosity) in hematologic malignancies

Useful in patients with <20 normal metaphases or with no mitosis to consider on conventional cytogenetics

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 in the following

  • ALL – balanced t( 9;22) (BCR-ABL1)), t(12;21) (ETV6-RUNX1), and balanced rearrangement of MLL, IGH, MYC, and TCF3
  • AML – balanced t( 15;17) (PML-RARA),  t(8;21) (RUNX1-RUNX1T1), and balanced rearrangement of the MLL or the CBFB gene

Does not detect base pair mutations and very small deletions/duplications; imbalances of the mitochondrial genome; low level clones (not recommended for MRD)

 
Chromosome FISH, Interphase 2002298
Method: Fluorescence in situ Hybridization

Identify specific translocations and rearrangements in hematopoietic neoplasms

May aid in classification, prognostication, and therapeutic monitoring of AML

Specific FISH probes related to AML must be requested and include

  • -5/del(5q)
  • -7/del(7q)
  • +8
  • del(20q)
  • MLL rearrangements (11q23)
  • EVI1 (inv(3) or t(3q))
  • RUNX1/RUNX1T1 fusion (t(8;21))
  • PML/RARA fusion (t(15;17))
  • CBFB rearrangement (inv(16) or t(16q))

ARUP Oncology FISH Probes menu

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

Repeat testing as clinically indicated to monitor disease progression

Acute Myelogenous Leukemia Panel by FISH 2002384
Method: Fluorescence in situ Hybridization

Identify prognostically important translocations in newly diagnosed AML

May be used to monitor response to therapy or progression of disease

Adjunct to conventional cytogenetic (CC) studies

FISH is more sensitive than CC in detecting certain genomic aberrations

Probes include

  • PML-RARA t(15;17)
  • RUNX1-RUNX1T1 t(8;21)
  • CBFB-MYH11 inv(16)/t(16;16)
  • MLL 11q23 rearrangements
   
PML-RARA Translocation by FISH 2002363
Method: Fluorescence in situ Hybridization

Use for rapid genetic confirmation of acute promyelocytic leukemia (APL)

Clinical sensitivity – >97%

Clinical specificity – essentially diagnostic for APL in the correct clinical context

Analytical sensitivity/specificity – >95%

FISH provides no information about the isoform of PML-RARA, which is required for molecular monitoring of MRD

Variant translocation involving RARA and partner genes other than PML occur in a small subset of patients and may be suggested by this FISH assay but will need additional testing for confirmation

Cannot be used for monitoring MRD (inadequate sensitivity)

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

Use in conjunction with conventional cytogenetics for diagnosis and prognosis in therapy-related MDS or AML associated with MDS

Probes include

  • del(5q)
  • monosomy 7 or 7q deletion
  • 11q23 rearrangements

Chromosome alterations outside regions complementary to these probes are not detected

 
CBFB-MYH11, inv(16) by RT-PCR 0092209
Method: Reverse Transcription Polymerase Chain Reaction

Detection of CBFB-MYH11 in AML; also called core-binding factor-related (CBF) AML

Type A and D/E fusion transcripts can be detected

Analytical sensitivity – 1 in 103

Not a quantitative test; cannot be used for minimal residual disease monitoring

Bone marrow samples preferred for maximum sensitivity

Poor RNA yield will lead to false negatives – more common with peripheral blood

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

Detect and quantitate RUNX1-RUNX1T1 fusions arising from t(8;21) in AML

“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

Initial test for prognostication of CN-AML

   
CEBPA Mutation Detection 2004247
Method: Polymerase Chain Reaction/Sequencing

Initial test for prognostication of CN-AML

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

Initial test for prognostication of CN-AML

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

Secondary test for prognostication of CN-AML

Analytical sensitivity – 40% mutated cells

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

Secondary test for prognostication of CN-AML

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

Provide diagnostic, prognostic, and predictive information for

  • AML associated with inv(16) or t(8;21) (also known as core binding factor (CBF) AML
  • Mastocytosis
  • Gastrointestinal stromal tumors (GISTs)
  • Melanoma

Analytical sensitivity – detects mutations in

  • Exon 17 in specimens with at least 30% AML cells carrying the mutation
  • Exon 8 in samples with at least 5% AML cells carrying the mutation

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

Diagnosis, prognosis, and monitoring for newly diagnosed acute or chronic leukemia with eosinophilia

Probes include PDGFRA, PDGFRB, FGFR1, and CBFB

   
CD19 by Immunohistochemistry 2005114
Method: Immunohistochemistry

Aid in histologic diagnosis of B-cell leukemia/lymphoma

Stained and returned to client pathologist for interpretation; consultation available if needed

   
CD34, QBEnd/10 by Immunohistochemistry 2003556
Method: Immunohistochemistry

Aid in the histologic diagnosis of AML

Stained and returned to client pathologist for interpretation; consultation available if needed

   
CD68, KP1 by Immunohistochemistry 2003598
Method: Immunohistochemistry

Aid in the histologic diagnosis of AML

Stained and returned to client pathologist for interpretation; consultation available if needed

   
CD79A by Immunohistochemistry 2003800
Method: Immunohistochemistry

Aid in the histologic diagnosis of AML

Stained and returned to client pathologist for interpretation; consultation available if needed

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

Aid in the histologic diagnosis of AML

Stained and returned to client pathologist for interpretation; consultation available if needed

   
Myeloperoxidase Stain 0049030
Method: Cytochemical Stain

Determine myeloid lineage in AML per WHO classification

Less sensitive and specific than flow cytometry immunophenotype

   
Pax-5 by Immunohistochemistry 2004082
Method: Immunohistochemistry

Aid in the histologic diagnosis of AML

Stained and returned to client pathologist for interpretation; consultation available if needed

   
Lysozyme (Muramidase) by Immunohistochemistry 2003990
Method: Immunohistochemistry

Aid in the histologic diagnosis of AML

Stained and returned to client pathologist for interpretation; consultation available if needed

   
Additional Tests Available
 
Click the plus sign to expand the table of additional tests.
Test Name and NumberComments
PML-RARA Translocation, t(15;17) by RT-PCR, Quantitative 2002871
Method: Reverse Transcription Polymerase Chain Reaction

May be used for genetic confirmation of APL; however, FISH is more rapid and is the recommended test

Assess therapeutic response and monitor for MRD

Primer sets are designed to detect all 3 gene fusion patterns: type A (short, S-form, bcr-3), type B (long, L-form, bcr-1) and type B variant (variable, V-form, bcr-2)

Clinical sensitivity – >97%

Clinical specificity – essentially diagnostic for APL in the correct clinical context

Analytical sensitivity – 1 in 104

Analytical specificity – 85%

Bone marrow samples preferred for maximum sensitivity

Poor RNA yield will lead to false negatives (more common with peripheral blood)

Translocations involving other genes or gene partners will not be detected

Chromosome Analysis, Bone Marrow 2002292
Method: Giemsa Band

Diagnosis, prognosis, and monitoring of MRD in therapy-related MDS and AML

Repeat testing as clinically indicated to monitor disease progression

Chromosome Analysis, Leukemic Blood 2002290
Method: Giemsa Band

Detect chromosome abnormalities in peripheral blood consistent with diagnosis of AML

Prognosis in AML

Number of dividing cells in the peripheral blood may be insufficient to allow for full analysis of metaphase cells; bone marrow aspirate may be more informative

CBC with Platelet Count 0040002
Method: Automated Cell Count

Screen for blasts and cytopenias

Prothrombin Time 0030215
Method: Electromagnetic Mechanical Clot Detection

Screen for DIC related to acute promyelocytic leukemia

Partial Thromboplastin Time 0030235
Method: Electromagnetic Mechanical Clot Detection

Screen for DIC related to acute promyelocytic leukemia

Fibrinogen 0030130
Method: Electromagnetic Mechanical Clot Detection

Screen for DIC related to acute promyelocytic leukemia

D-Dimer 0030057
Method: Immunoturbidimetry

Screen for DIC related to acute promyelocytic leukemia

Myeloperoxidase (MPO) by Immunohistochemistry 2004014
Method: Immunohistochemistry

Aid in the histologic diagnosis of AML

Stained and returned to client pathologist for interpretation; consultation available if needed

IDH1 R132H Point Mutation with Interpretation by Immunohistochemistry 2007357
Method: Immunohistochemistry

Sequencing is preferred