Myeloproliferative Neoplasms - MPN

Key Points

Molecular Genetics of BCR-ABL1 Negative Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPNs) are associated with dysregulation of tyrosine kinases, leading to abnormal downstream signaling of pathways and increased cellular proliferation. The presence of the BCR-ABL1 mutation characterizes chronic myelogenous leukemia (CML). For BCR-ABL1-negative MPNs, new molecular markers have implications for further classification and diagnosis. 

Content in tables below based on Chaligné R et al, 2007; Guglielmelli P et al, 2009;  Pardanani AD et al, 2006; Schmidt AE et al, 2012; Vainchenker W et al, 2011; Vakil E et al, 2011.

JAK2
JAK2 (janus kinase 2)
Mutations

Chromosome location – 9p24

JAK2 V617F mutation

  • Prototypical tyrosine kinase mutation  
  • Gain-of-function in exon 14

JAK2 exon 12 mutation

  • Next most common mutation site
  • Missense, insertion, or deletion mutations
  • Observed in JAK2 V617F-negative clones

Occurs less frequently in essential thrombocythemia (ET) or primary myelofibrosis (PMF)

Mutation Prevalence

JAK2 V617F mutation

JAK2 exon 12 mutation

  • Present in the majority of patients with PV who are JAK2 V617F-negative, but rarely occurs in PMF, ET
Biology

Cytoplasmic tyrosine kinase activates JAK-STAT pathway, leading to cytokine-independent growth

Disease Association

PV

ET

PMF

Indications

JAK2 V617F mutation

  • Laboratory tests suggestive of MPN
  • Unexplained erythrocytosis or thrombocytosis; bone marrow fibrosis; BCR-ABL1-negative granulocytosis; unexplained monocytosis or splenomegaly; aquagenic pruritus
  • Symptoms characteristic for MPN
    • Aquagenic pruritus
    • Unusual thrombotic events (eg, splanchnic vein thrombosis, Budd-Chiari)
    • Unexplained splenomegaly
  • Blood and bone marrow testing are equivalent – performing both is unnecessary

JAK2 exon 12 mutation

  • Subnormal erythropoietin and negative JAK2 V617F and CALR testing with symptoms and laboratory test results suggestive of MPN

Quantitative testing

  • May be useful in assessment of residual disease after stem cell transplant
  • Enhances diagnostic certainty in cases with low mutant allelic burden       
Clinical Implications

JAK2 inhibitors are in development

  • Decrease in mutant JAK2 V617F allelic burden may not correlate with clinical response  
  • Utility of monitoring mutant allelic burden is under investigation

JAK2 V617F mutation

  • Useful in classifying the disease process as MPN
  • Not useful in classifying specific MPN subtypes
    • High mutant allelic burden – more likely PV
    • Diagnosis based on clinical factors
  • Lower JAK2 V617F allele burden in PMF is associated with poor outcome (Guglielmelli, 2009)
ARUP Tests

JAK2 Gene, V617F Mutation, Qualitative  0051245

JAK2 Gene, V617F Mutation, Quantitative  0040168

JAK2 Exon 12 Mutation Analysis by PCR  2002357

CALR

CALR (calreticulin)

Mutations

Chromosome 19p13.3-13.2

  • Exon 9 insertion/deletion

Mutation Prevalence

Essential thrombocythemia (ET) – 67% of JAK2- and MPL-negative cases

Primary myelofibrosis (PMF) – 88% of JAK2- and MPL-negative cases

Biology

CALR gene encodes a calcium-binding chaperone protein involved in glycoprotein folding and calcium homeostasis

Disease Association

ET

PMF

Absent in PV

Indications

JAK2-negative patients when suspicion is high for MPN (excluding PV)

Clinical Implications

Diagnostic for JAK2- and MPL-negative MPN

Prognosis – CALR-mutated ET and PMF are associated with increased overall survival when compared with JAK2- and MPL-mutated ET/PMF

CALR-mutated ET is associated with a decreased incidence of thrombosis when compared to JAK2-mutated ET

ARUP Available Test

CALR (Calreticulin) Exon 9 Mutation Analysis by PCR 2010673

PDGFRA, PDGFRB, and FGFR1

PDGFRA (platelet derived growth factor receptor, alpha-polypeptide)

PDGFRB (platelet derived growth factor receptor, beta-polypeptide)

FGFR1 (fibroblast growth receptor 1)

Mutations

Chromosome location

  • 4q12 – PDGFRA
  • 5q31-33 – PDGFRB 
  • 8p11 – FGFR1 

Translocations cause fusion genes

Mutation Prevalence

FIP1L1-PDGFRA fusion, PDGFRB translocations, or FGFR1 translocations – most common in MPNs associated with eosinophilia

FGFR1 mutations – also associated with myeloid and lymphoid neoplasms  

PDGFR mutations – also found in chronic myelomonocytic leukemia, atypical chronic myelogenous leukemia, and, rarely, chronic eosinophilic leukemia

Biology

PDGFRA and PDGFRB are receptor kinases that regulate cell growth and proliferation

FGFR1 promotes proliferation and survival of eosinophils

Disease Association

Eosinophilic disease

Indications

Unexplained persistent eosinophilia

Presence of any of these mutations precludes the diagnosis of eosinophilic leukemia or hypereosinophilic syndrome

  • Cases should be assigned to the corresponding molecularly defined categories

Cytogenetics may be negative for FIP1L1-PDGFRA fusion

  • Use fluorescence in situ hybridization (FISH) analysis for detection of mutations if high suspicion

FGFR1 mutations usually identified by conventional cytogenetics or FISH

Clinical Implications

Tyrosine kinase inhibitor (TKI) sensitivity (imatinib)

  • FIP1L1-PDGFRA fusion – sensitive
  • PDGFRB translocation –  sensitive
  • FGFR1 mutation – not enough data to determine

Acquired resistance is common – sorafenib may be alternative inhibitor to use  

ARUP Tests

Myeloproliferative Disorders Panel by FISH 2002360

Eosinophilia Panel by FISH 2002378

Chromosome Analysis, Bone Marrow 2002292

KIT

KIT (v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog or mast/stem cell growth factor receptor)

Mutations

Chromosome location – 4q12

D816V mutation of the tyrosine kinase domain of the KIT gene

Rare (<5%) juxtamembrane KIT mutations

Mutation Prevalence

80% of patients with systemic mastocytosis (KIT D816V mutation)

Biology

KIT (CD117) is a type III tyrosine kinase

KIT expression is down-regulated upon differentiation of hematopoietic cells except for mast cells

KIT binding to its ligand (stem cell factor) regulates proliferation and maturation

Disease Association

Systemic mastocytosis

Indications

Clinical suspicion for systemic mastocytosis

Bone marrow with IHC positive for CD117 and flow cytometry positive for CD117, CD25, and CD2 confirm diagnosis

Clinical Implications

Tyrosine kinase inhibitor (TKI) sensitivity (imatinib)

  • Sensitive
    • KIT D816V-negative
    • Rare KIT juxtamembrane domain mutations
  • Resistant
    • KIT D816V-positive
ARUP Tests

Myeloproliferative Disorders Panel by FISH 2002360

Eosinophilia Panel by FISH 2002378

Chromosome Analysis, Bone Marrow 2002292

CD117 (c-Kit) by Immunohistochemistry 2003806

Leukemia/Lymphoma Phenotyping by Flow Cytometry 2008003

MPL

 MPL (myeloproliferative leukemia virus oncogene)

Mutations

Chromosome location – 1p34

MPL W515L or MPL W515K (rarely W515A, W515R) 

  • Resides on exon 10
  • Most common mutations
  • Activates JAK-STAT signaling

Observed in JAK2 V617F-negative clones

Mutation Prevalence

Essential thrombocythemia (ET) – 3-4%

Primary myelofibrosis (PMF) – 8-10%

Polycythemia vera (PV) – rare

Biology

Activating mutation of the thrombopoietin receptor causes activation of downstream signaling

Contributes to megakaryocytic myeloproliferation

Disease Association

ET

PMF

Indications

JAK2 V617F (including exon 12)-negative individuals when suspicion for an MPN is high

  • Examples
    • Thrombocytosis and morphologically equivocal for ET
    • Marrow fibrosis and morphologically equivocal for PMF
Clinical Implications

Diagnostic for JAK2-negative MPN

ARUP Tests

MPL codon 515 Mutation Detection by Pyrosequencing, Quantitative  2005545

Diagnosis

Indications for Testing

  • Refer to Key Points section

Criteria for Diagnosis

  • Polycythemia vera (PV)

    Must exclude secondary causes of erythrocytosis

    2008 WHO diagnostic criteria – must meet both major and 1 minor criteria or the first major and 2 minor criteria

    • Major criteria
      • Evidence of increased RBC volume, including ≥1 of the following
        • Hgb >18.5 g/dL (men), >16.5 g/dL (women)
        • Hgb or Hct >99th percentile of reference
        • Elevated red cell mass >25% above mean predicted
        • Hgb >17 g/dL (men) or >15 g/dL (women) if associated with sustained increase of ≥2 g/dL not attributed to correction of iron deficiency anemia
      • Presence of JAK2 V617 (90-95%) or JAK2 exon 12 mutations (5-10%)
    • Minor criteria
      • Bone marrow trilineage proliferation
      • Subnormal serum erythropoietin level
      • Endogenous erythroid colony growth in vitro
    Essential thrombocythemia (ET)

    Must exclude other causes of thrombocytosis

    • Reactive
      • Anemias
        • Iron deficiency
        • Hemolytic
        • Acute blood loss
    • Post splenectomy
    • Inflammatory disorders

    2008 WHO criteria – must meet all 4 criteria

    • Sustained elevation of platelets ≥450x109/L 
      • Defined as at least 2 measurements, 2 months apart
    • Bone marrow – megakaryocyte proliferation with little or no granulocyte/erythrocyte proliferation
    • Does not meet WHO criteria for BCR-ABL1-positive chronic myelogenous leukemia, polycythemia vera, primary myelofibrosis, myelodysplastic syndromes, or other myeloid neoplasm
    • Demonstration of JAK2 V617F (50%), MPL gene mutations (eg, W515L and W515K), or no evidence of reactive thrombocytosis

    Other criteria

    • Bone marrow biopsy
      • Normal to hypercellular with increased megakaryocytes
      • Stainable iron
      • Normal red cell blood mass
      • No significant collagen or reticulin fibrosis
    Primary myelofibrosis (PMF)

    2008 WHO criteria – must meet all 3 major and 2 minor criteria

    • Major criteria
      • Megakaryocyte proliferation and atypia accompanied by reticulin or collagen fibrosis, or, in the absence of reticulin fibrosis, megakaryocyte changes must be accompanied by increased marrow cellularity
      • Does not meet WHO criteria for BCR-ABL1-positive chronic myelogenous leukemia, polycythemia vera, myelodysplastic syndromes, or other myeloid neoplasm
      • JAK2 V617F or other clonal markers (eg, MPL W515K/L) or no evidence of reactive fibrosis
    • Minor criteria
      • Leukoerythroblastosis
      • Increased serum lactate dehydrogenase
      • Anemia
      • Splenomegaly

Laboratory Testing

  • Initial testing – CBC with differential, erythropoietin level, uric acid, lactate dehydrogenase
  • Rule out most common causes of anemia
  • Refer to Key Points section

Histology

  • Noneosinophilic MPN (so-called "classic MPNs")
    • Bone marrow examination is generally performed after JAK testing
      • Cytogenetic analysis
  • Eosinophilic MPN
    • Molecular testing
      • Myeloid neoplasms associated with eosinophilia and abnormalities in PDGFRA, PDGFRB, or FGFR1
      • Cytogenetic and fluorescence in situ hybridization analysis for detection of FIP1L1-PDGFFA fusion, PDGFRB (5q33) translocations, or FGFR1 (8p11) translocations
      • MPN Subtypes, Features, and Diagnostic Criteria

        MPN Subtypes, Features, and Diagnostic Criteria

        WHO Classification

        Features

        Laboratory

        AML with inv(16)(p13.1q22) or t(16;16)(p13.1;q22); CBFB-MYH11

        Presents as acute myeloid leukemia (AML)

        Myeloid sarcomas may be present at initial diagnosis or relapse

        Morphology – acute myelomonocytic leukemia with increased eosinophils containing immature eosinophilic granules in the bone marrow

        • Peripheral eosinophilia is unusual
        • Diagnosis of AML even if blasts <20%

        Genetics

        • inv(16)(p13.1q22) or t(16;16)(p13.1;q22) found in most cases
          • inv(16)(p13.1q22) is found in vast majority
          • FISH or PCR may be necessary to document this genetic alteration
        • Secondary cytogenetic abnormalities – +22, +8, del(7q)
        • KIT mutations may be present

        Myeloid and lymphoid neoplasms with PDGFRA rearrangement

        Most frequently presents as chronic eosinophilic leukemia (CEL), but may present as AML, T-cell lymphoblastic lymphoma (T-LBL), or both

        • Acute transformation can follow CEL presentation

        Organ infiltration by eosinophils

        • Heart
        • Lungs
        • CNS
        • GI tract

        Splenomegaly in majority of patients

        Pronounced male predominance

        Morphology

        • Peripheral blood and bone marrow eosinophilia – markedly elevated
        • Typically <20% blasts in peripheral blood and bone marrow
        • Increased bone marrow mast cells common

        Genetics

        • Absence of BCR-ABL1 fusion gene
        • Most commonly associated with FIP1L1-PDGFRA fusion
          • FISH or PCR is usually necessary to document this genetic alteration; cytogenetic studies are normal
        • Other fusion genes have rarely been identified

        Myeloid and lymphoid neoplasms with PDGFRB rearrangement

        Presents with features of chronic myelomonocytic leukemia – usually with eosinophilia

        Splenomegaly in majority of patients

        Male predominance, but much less marked than PDGFRA-associated neoplasms

        Morphology

        • Peripheral leukocytosis
        • Hypercellular bone marrow with typically <20% blasts
        • Increased bone marrow mast cells common

        Genetics

        • Most common translocation – t(5;12)(q31-33;p13) resulting in formation of ETV6-PDGFRB

        Myeloid and lymphoid neoplasms with FGFR1 abnormalities

        Often presents with peripheral eosinophilia in the context of lymphadenopathy and lymphoblastic leukemia/lymphoma

        Slight male predominance

        Morphology

        • AML, acute lymphoblastic leukemia (ALL), CEL – usually associated with peripheral blood or bone marrow eosinophilia

        Genetics

        • Presence of t(8;13)(p11;q12) or a variant translocation at the 8p11 breakpoint leading to FGFR1 rearrangement
        • Secondary cytogenetic abnormalities – trisomy 21 most often observed
      • In the absence of these molecular markers, chronic eosinophilic leukemia (CEL), not otherwise specified (NOS) (CEL-NOS), or hypereosinophilic syndrome (HES) should be considered
        • Diagnosis in both CEL-NOS and HES requires the following
          • Presence of ≥1.5x109/L eosinophil count – peripheral blood
          • Exclusion of secondary eosinophilia
          • Exclusion of other acute or chronic myeloid neoplasm
          • No evidence for phenotypically abnormal or clonal T lymphocytes
        • Diagnosis of HES requires the absence of both cytogenetic abnormality and ≥2% peripheral blasts or ≥5% bone marrow blasts
  • Mast cell MPNs – CD117 (c-Kit), CD25 testing

Prognosis

  • Classic MPN
    • JAK2 V617F – quantitative testing may predict degree of fibrosis, thrombotic tendencies, or survival
    • Karyotyping in PMF
      • Unfavorable – complex karyotype or ≥1 abnormality, including +8, -7/7q-, i(17q), -5/5q-, 12p-, inv(3), or 11q23
  • Eosinophilic MPN
    • inv(1) – favorable prognosis, unless associated with KIT mutation
    • PDGFRA and PDGFRB – good prognosis with favorable response to tyrosine kinase inhibitors (TKIs)
    • FGFR1 – poor prognosis with unclear response to TKIs

Differential Diagnosis

Clinical Background

Myeloproliferative neoplasms (MPN) are a group of slow-growing blood cancers, including chronic myelogenous leukemia (CML). MPNs present with clonal proliferation of abnormal hematopoietic cells that involve bone marrow and peripheral blood.
2008 WHO Classification of Myeloid Neoplasms and Acute Leukemia

Myeloproliferative neoplasms (MPN)

  • CML, BCR-ABL1-positive1
  • Chronic neutrophilic leukemia
  • Polycythemia vera1
  • Primary myelofibrosis1
  • Essential thrombocythemia1
  • Chronic eosinophilic leukemia (CEL), not otherwise specified (NOS)
  • Mastocytosis
    • Cutaneous mastocytosis
    • Systemic mastocytosis
    • Mast cell leukemia
    • Mast cell sarcoma
    • Extracutaneous mastocytoma
  • MPN, unclassifiable
Myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB, or FGFR1 gene

Myelodysplastic/myeloproliferative neoplasms

  • Chronic myelomonocytic leukemia
  • Atypical CML, BCR-ABL1-negative
  • Juvenile myelomonocytic leukemia
  • Myelodysplastic/myeloproliferative neoplasm, unclassifiable
  • Refractory anemia with ring sideroblasts associated with marked thrombocytosis2
Myelodysplastic syndromes
Acute myeloid leukemia (AML) and related precursor neoplasms
Acute leukemias of ambiguous lineage
1Considered classic MPN
2Provisional listing; subject to change

Selected MPNs

  • Polycythemia vera (PV)

    Epidemiology

    • Erythroid dominant trilineage proliferation of hematopoietic precursor cells
    • Incidence – 2.8/100,000
    • Age – peaks in 50s-60s
    • Sex – M>F (minimal)

    Clinical Presentation

    • Insidious onset
    • Thrombotic complications
    • Bleeding complications – often associated with acquired von Willebrand disease
      • Epistaxis
      • Oral mucosal hemorrhage
      • Gastrointestinal hemorrhage
      • Ecchymoses
    • Hyperviscosity syndrome – less common
      • Hypertension
      • Headache
      • Dizziness
      • Visual disturbances
      • Claudication
    • Erythromelalgia
      • Redness and burning of palms and plantar areas of feet – sometimes progressing to necrosis of digits
    • Gouty arthritis
    • Pruritus
    • Hepatosplenomegaly
    • Transformation to myelofibrosis (or spent phase) – short survival
    • Transformation to acute leukemia – always fatal without allogeneic bone marrow transplant
    Essential thrombocythemia (ET)

    Epidemiology

    • Thrombocytosis and abnormal megakaryocyte proliferation with clonal proliferation of pluripotent stem cells
    • Incidence – 1.5/100,000
    • Age – peaks in 50s 
      • Secondary peak in 20s – mainly females; M<F, 1:2
    • Sex – M:F, equal 

    Clinical Presentation

    • Arterial thrombosis
      • Brain
      • Cardiac
      • Extremities
    • Venous thrombosis
    • Bleeding complications
    • Many patients are asymptomatic and do not require therapy
    • Transformation to myelofibrosis (or spent phase) in <10% of cases – short survival
    • Transformation to acute leukemia in <5% of cases – always fatal without allogeneic bone marrow transplantation
    Primary myelofibrosis (PMF)

    Epidemiology

    • Clonal stem cell deficit characterized by panmyelosis with intact maturation, progressive bone marrow fibrosis, splenomegaly, multiorgan extramedullary hematopoiesis
    • Incidence – 0.3-1.5/100,000 per year
    • Age – mean is 67 years
    • Sex – M:F, equal

    Clinical Presentation

    • May be a secondary process in polycythemia vera and essential thrombocythemia
    • Shortest survival of all MPNs
    • Some with insidious onset and stable; others rapidly progressing
    • Acute leukemic transformation common
    • Symptoms, physical and laboratory findings
      • Hypercatabolic state – fever, weight loss, night sweats
      • High-output cardiac failure from increased plasma volume
      • Blood abnormality – dacryocytes (tear drops), leukoerythroblastic morphology
      • Other blood abnormalities – anemia, leukocytosis, leukopenia, thrombocytosis, thrombocytopenia, increased circulating blasts
      • Fatigue unrelated to anemia
      • Dyspnea secondary to anemia
      • Petechia secondary to thrombocytopenia
      • Gout
      • Splenomegaly – 100% of patients
      • Hepatomegaly – 50% of patients

Pediatrics

Myeloproliferative neoplasms are extremely rare in children.

Polycythemia vera (PV)

Epidemiology

  • Incidence – rare
  • Age
    • <0.1% with PV are <20 years
    • Two peaks – 5-6 years, 10-14 years

Clinical Presentation

  • Thromboses
    • Arterial – stroke
    • Venous – Budd-Chiari syndrome
  • Bleeding disorders
  • Splenomegaly common
  • Rubor
  • Pruritus – especially after hot bath
  • Erythromelalgia

Diagnosis

Indications for Testing

  • Refer to Key Points section

Criteria for Diagnosis

  • See Diagnosis tab for PV criteria

Laboratory Testing

  • Initial diagnosis – CBC with differential, uric acid, lactate dehydrogenase
  • Refer to Key Points section

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
Erythropoietin 0050227
Method: Quantitative Chemiluminescent Immunoassay

Initial test for MPN

Use to identify or exclude polycythemia vera (PV) – minor criteria

   
JAK2 Gene, V617F Mutation, Qualitative 0051245
Method: Polymerase Chain Reaction

Reasonable screening test for routine evaluation of unexplained erythrocytosis, thrombocytosis, BCR-ABL1-negative granulocytosis, and bone marrow fibrosis

Appropriate screen in individuals with symptoms characteristic for BCR-ABL1-negative MPN

  • Unusual thrombotic events (eg, splanchnic vein thrombosis, Budd-Chiari)
  • Aquagenic pruritus
  • Unexplained splenomegaly

Clinical sensitivity

  • PV – 90-95%
  • ET and PMF – ~50%

Only one point mutation is detected; exon 12 mutations are not detected

Limit of detection is 0.5% mutant allele

Bone marrow biopsy

Can confirm result with JAK2 V617F mutation, quantitation testing

JAK2 Gene, V617F Mutation, Quantitative 0040168
Method: Polymerase Chain Reaction

Enhances diagnostic certainty in suspected cases with low mutant allelic burden 

Aids in minimal residual disease (MRD) monitoring post stem cell transplant 

Clinical sensitivity

  • PV – 95%
  • ET and PMF – ~50%

Exon 12 mutations are not detected

Limit of detection is 0.2% mutant allele

Bone marrow biopsy
JAK2 Exon 12 Mutation Analysis by PCR 2002357
Method: Polymerase Chain Reaction

Most appropriate in cases of high suspicion of PV with negative JAK2 V617F and CALR exon 9 mutations

Clinical sensitivity

  • PV – 2%

Only exon 12 mutations are detected

Limit of detection is 1/1,000 cells

 
MPL codon 515 Mutation Detection by Pyrosequencing, Quantitative 2005545
Method: Polymerase Chain Reaction/Quantitative Pyrosequencing

May be useful when suspicion for MPN is high in JAK2 V617F (including exon 12)-negative individuals

Possible clinical scenarios

  • Thrombocythemic individuals with BM morphologically equivocal for ET
  • Individuals with BM fibrosis but equivocal for PMF morphologically
  • Cases where ruling out a reactive thrombocytosis is difficult

Clinical sensitivity

  • ET – 3-4%
  • PMF – 8-10%
  • PV – very rare

Does not detect mutations in other locations within the MPL gene

Limit of detection for this test is 5% mutant allele

 
CALR (Calreticulin) Exon 9 Mutation Analysis by PCR 2010673
Method: Polymerase Chain Reaction/Capillary Electrophoresis

Diagnosis and subclassification of ET and PMF patients who lack JAK2 mutations

CALR mutations are absent in PV patients

Detects only exon 9 insertion/deletion mutations; does not detect mutations in other regions of the CALR gene

 
Myeloproliferative Disorders Panel by FISH 2002360
Method: Fluorescence in situ Hybridization

Provides prognostic and predictive information in MPNs presenting with eosinophilia

Probes include BCR-ABL1,PDGFRA, PDGFRB, FGFR1

Detects only rearrangements targeted by the probes

 
Eosinophilia Panel by FISH 2002378
Method: Fluorescence in situ Hybridization

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

Probes included to detect mutations in the following genes – PDGFRA, PDGFRB, FGFR1, and CBFB

Does not detect rearrangements associated with chronic myelogenous leukemia

Translocation partners of PDGFRB gene on chromosome 5q33 and FGFR1 gene on chromosome 8p11 not identified by this test

 
Chromosome Analysis, Bone Marrow 2002292
Method: Giemsa Band

Detect chromosome abnormalities in bone marrow for suspected acute or chronic leukemia with eosinophilia

Can also aid in distinguishing this class of hematologic disorders from CML

 

Repeat testing as clinically indicated to monitor disease progression

Chromosome FISH, Interphase 2002298
Method: Fluorescence in situ Hybridization

May aid in classification, prognostication, and therapeutic monitoring

Specific FISH probes must be requested and for this indication include probes for PDGFRA, PDGFRB, +8, +9, 20q deletion, monosomy 7/7q deletion, 5q deletion, and 13q deletion

ARUP Oncology FISH Probes menu

Limit of detection is probe dependent and around 2-5% in interphase nuclei

Many of these abnormalities can also be detected in myelodysplastic syndromes and AML and are therefore not sufficient for diagnosis but are consistent with the suspected diagnosis (exceptions are mutations in PDGFRA and PDGFRB, which are specific for MPNs)

Repeat testing as clinically indicated to monitor disease progression

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

Aid in histologic diagnosis of MPN

Stained and returned to client pathologist; consultation available if needed

   
CD25 by Immunohistochemistry 2003544
Method: Immunohistochemistry

Aid in histologic diagnosis of MPN

Stained and returned to client pathologist; consultation available if needed

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

Aid in evaluation of hematopoietic neoplasms (eg, 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

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

Myeloid/Monocyte: CD11b, CD13, CD14 (Mo2), CD14 (MY4), CD15, CD33, CD64, CD117, myeloperoxidase

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

   
Oxygen Dissociation (P50) by Hemoximetry 2002984
Method: Spectrophotometry/Clark Electrode

Use when JAK2 testing is negative and PV is present

   
von Hippel-Lindau (VHL) Sequencing 2002970
Method: Polymerase Chain Reaction/Sequencing

Use when JAK2 testing is negative and PV is present

Large deletions and duplications, deep intronic mutations, and regulatory region mutations are not detected

Rare diagnostic errors may occur due to primer-site mutations

PV due to causes other than VHL gene mutations are not detected

 
Additional Tests Available
 
Click the plus sign to expand the table of additional tests.
Test Name and NumberComments
CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Initial screen for MPN

EPOR Mutation Detection by Sequencing 2007914
Method: Polymerase Chain Reaction/Sequencing

Confirm a diagnosis of primary familial or congenital polycythemia (PFCP)