L24 - MDS and MPN: principles of diagnosis and treatment Flashcards

1
Q

Spectrum of MDS/MPN?

A

Myeloproliferative neoplams (MPN)

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN)

Myelodysplastic syndromes (MDS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Definition of MDS? (3 features)

A

clonal haematological disorder with:

1) ineffective haematopoiesis
2) cytopenia
3) propensity of clonal progression to AML

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define the extent of cytopenia and bone marrow changes in MDS?

A

cytopenia in ≥ 1 lineage +/- increase in blasts of myeloid lineage

hypercellular bone marrow, significant morphologic dysplasia in ≥ 1 lineage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain why hypercullar BM in MDS causes cytopenia?

A

Hyperproliferative clonal cells undergo premature apoptosis&raquo_space; cytopenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Epidemiology of MDS?

A

Male preponderance (2:1)

Increasing incidence after 50s, median age = 75

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Spectrum of peripheral blood cytopenia in MDS?

A

 1 lineage: anaemia / neutropenia / thrombocytopenia

 2 lineages: bicytopenia

 3 lineages: pancytopenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the most common cause of macrocytic anemia in elderly?

A

MDS = ↑ mean corpuscular volume (MCV)

90% of patients have significant macrocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the most common RBC abnormality asso. with MDS?

A

significant macrocytosis (>100 fl)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Distinguish low grade and high grade MDS?

A

Low = Dysplasia without excess blasts + Low risk of AML progression

High = Dysplasia with excess blasts + high risk karyotype/ genetics + High risk of progression to AML in 2 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List the investigative results that confirm MDS? **

A

Proof of ineffective haematopoesis** and dysplasia +/- increase in blasts by BM and PB

confirm clonality**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List typical blood test results for MDS? (cells involved, vitb12, ldh?)

A

Red cell Macrocytosis + cytopenia + low reticulocyte count

Normal Vit B12, serum and RBC folate (ddx from B12 and folate dif.)

Usually normal LDH, elev. in high risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

List all the general investigations for suspected MDS?

A

Blood:

  • CBC with D/C and blood film review
  • Biochemistry: LDH, Serum active B12, Serum folate

Diagnostic:

  • BM aspiration and trephine biopsy to prove clonality and hypercellularity BM***
  • Cytogenetic and molecular studies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Main treatment regimen for low-grade MDS with very low to intermediate risk (IPSS-R test)?

A

Supportive (e.g. transfusion) +/- erythropoietic stimulating factors (e.g. EPO) + Granulocyte-colony stimulating factor (G-CSF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Main treatment regimen for high grade MDS with intermediate to very high risk (IPSS-R test)?

A
  • Hypomethylating agents (azacitidine, decitabine)

* Allogeneic HSCT in young and transplant-eligible patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Genetic pathogenesis of MDS?

A

Aberrant DNA methylation/ inactivation&raquo_space; suppress Tumour suppressant/ physiological genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

MoA of drugs used against high risk MDS?

A

Hypomethylating agents:

  • Azacitidine, Decitabine)
    1. Reactivation of silenced genes** (esp. tumour suppressor genes)
    2. Cytotoxicity
    3. Inhibit cellular proliferation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the blood cell abnormalities in MDS?

A

RBC:

  • Macrocytosis
  • Absent polychromasia/ Reticulotcytopenia

WBC:
- Leucopenia
• Hypolobated + hypogranular neutrophils
• No hypersegmented neutrophils (low B12)
(Pseudo PelgerHuët anomaly)

Plt:
- Thrombocytopenia with no platelet clumps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

DDx of pancytopenia with significant macrocytosis?

A

MDS

Pernicious anaemia (B12 def.)

AML or ALL with MDS-related changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Clinical presentation of MDS on P/E?

A

Abnormal bleeding tendencies(e.g. abnormal per-rectal bleeding/ menses)
Easy bruising
Fatigue, fever, frequent infections
Anaemic symptoms

LN, liver and spleen are NOT palpable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Typical BM histology in MDS? (think cellularity, erythoid cells, leukaemic cells, megakaryocytic cells appearance)

A
  • Hypercellular marrow* with mulitple lineage dysplasia
  • Some leukaemic blasts
  • Increased erythropoiesis with Bilobed erythoid cells
  • Micromegakaryocytes
  • Abnormally lobulated myeloid cells
  • Ring sideroblasts* upon iron stain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Is LRFT, LDH levels normal in MDS?

A

Yes

MDS is not proliferative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe the abnormal megakaryocyte morphology in MDS?

A

Micro-megakaryocytes

Separate nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Define MPN?

A

• A clonal haematopoietic stem cell disorder

> > proliferation of one or more of the haematopoietic lineages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Molecular pathogenesis of MPN?

A

Driver mutation/ gene fusion activate tyrosine kinases and cytokine signalling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Define the classes of MPN?
1) Philadelphia chromosome positive: - CML, BCR-ABL1 positive t(9;22) 2) Philadelphia chromosome negative: - chronic neutrophilic leukaemia - Polycythaemia vera - Essential thrombocythaemia - Primary myelofibrosis - Chronic eosinophilic leukaemia, NOS
26
Genetic hallmark of CML?
BCR-ABL1 t(9;22)
27
Genetic hallmark of Polycythaemia vera?
JAK2 V617F 9p24
28
Genetic hallmark of Essential thrombocythaemia and Primary myelofibrosis?
JAK2 V617F 9p24 | CALR exon 9 mutation
29
3 phases of CML and treatment option for each pahse?
chronic phase (CP), accelerated phase (AP) and blast phase (BP) tyrosine kinase inhibitors: CP Allo-HSCT = AP and BP
30
P/E features and clinical presentation of CML in Chronic phase?
50% asymptomatic Fever, weight loss, night sweat (like lymphoma) Splenomegaly***, Bone pain***
31
CBC findings of CML in Chronic phase?
- Very high leukocytosis - Anemia - Thrombocytosis - Absolute basophilia - bimodal prominence/ severe increase of neutrophils and myelocytes** Left shift = highly immature myeloid series in PB
32
BM findings of CML in Chronic phase?
- Hypercellular with increased M:E ratio, blasts < 10% - Entire myeloid series hypercellular with bimodal prominence - Dwarf Megakaryocytes: Increased micromegakaryocytes with hypolobulation
33
List 2 genetic diagnostic tests for CML?
Cytogenetic and FISH: identify ch. 9 and 22 translocation by karyotype Find ABL-1, BCR gene fusion by FISH
34
MoA of tyrosine kinase inhibitors?
Block ATP binding site on BCR-ABL Block phosphorylation of effector
35
Epidemiology of Polycythemia vera?
Median age 55-60 | 1-3 per 100,000
36
Clinical presentation of polycythemia vera? What usually precedes the condition?
- typically secondary to vascular disturbances* (e.g. DVT, stroke, thromboembolism) and increased red-cell mass - Fatigue, aquagenic pruritis*, gout, dizziness and headache - LOW EPO - Mild to moderate splenomegaly +/- hepatomegaly
37
CBC findings of polycythaemia vera? Marrow finding?
Increased RBC, WBC, Plt count Increased Hb, Hct Marked trillineage hyperplasia: panmyelosis pleomorphic, mature megakaryocyte
38
Epidemiology of essential thromocythaemia?
Median age 50-60 Peak in women in 30 0.5-1.8 per 100,000
39
Clinical presentation of essential thrombocythaemia? What condition must be excluded in the Ddx?
30-50% asymptomatic: must exclude reactive thrombocytosis Mostly blood flow abnormalities: - Headache, Dizziness or lightheadedness, - Fainting. - Chest pain - Temporary vision changes - Numbness or tingling of the hands and feet - Redness, throbbing and burning pain in the hands and feet (erythromelalgia)
40
CBC findings of essential thrombocythaemia?
marked isolated thrombocytosis*** with platelet anisocytosis*** Normal Hb, WBC
41
Marrow findings of essential thrombocythaemia?
proliferation mainly of the megakaryocyte lineage increased number of large, mature megakaryocytes with hyperlobulated nuclei
42
What is the most common inherited bleeding disorder?
Inherited von Willebrand disease (VWD)
43
Epidemiology of Primary myelofibrosis?
Median age at diagnosis 65-70 • Both genders
44
Clinical presentation of Primary myelofibrosis
Prefibrotic stage or Overt fibrotic phase: Anaemic symptoms (i.e. lower exercise tolerance, pallor) Loss appetite, weight loss Easy bruising, abnormal bleeding massive splenomegaly, hepatomegaly, portal hypertension from hepatic fibrosis
45
CBC findings of Primary myelofibrosis?
leucocytosis, anaemia and thrombocytosis leucoerythoblastic blood picture: increased immature WBC and RBC tear-drop poikilocytes (RBC deform in spleen) many giant platelets
46
Marrow findings of Primary myelofibrosis?
- increased BM cellularity* - Thickened bony trabeculae, - Marked coarsening of reticulin fibres - Increased granulopoiesis and megakaryopoiesis* - reduced erythropoiesis* - Megakaryocytes: nuclear atypia, clustering*
47
Which disease causes must be excluded when investigating PV, ET, MF? What are the 2 most important investigations for accurate Dx of PV,ET or MF?
Exclusion of CML BCR-ABL1+ Exclusion of reactive causes without somatic mutations Must Proof clonality by cytogenetic and molecular studies + Morphological Dx by PB & BM
48
List the 3 diagnostic investigations for MPN?
* BMA and trephine biopsy * Cytogenetic analysis * Molecular studies (JAK2, CALR, MPL and BCR-ABL1 to exclude CML)
49
List the blood metrics tested for MPN?
CBC with differential count and blood film review - Clotting profile + exclusion of aVWD - Low EPO level (ddx for PV) - LRFT, LDH, urate - Hepatitis B and C serology
50
3 main risk factors for thrombosis in PV?
High risk: • Age > 60 OR • History of thrombosis + CVS risk factors (i.e. hypertension, smoking) • JAK2V617F
51
What is assessed to determine Primary myelofibrosis risk?
Various genetic mutations, CBC findings and marrow behavior
52
Treatment regimen for low risk Polycythaemia vera?
1. Low dose aspirin + Phlebotomy to maintain Hct <45% 2. Manage CVS risk factors and monitor for bleeding, thrombosis (Evaluate indications for cytoreductive therapy)
53
Treatment regimen for high risk Polycythaemia vera?
1. Low dose aspirin + Phlebotomy to maintain Hct <45% 2. Manage CVS risk factors and monitor for bleeding, thrombosis 3. cytoreductive therapy**: Hydroxyurea or Peg-IFNα 2A
54
Treatment regimen for very low, low risk and intermediate risk essential thrombocythaemia?
1. Aspirin 2. Monitor for CVS risk factors, new thrombosis, bleeding 3. Monitor for acquired vWD 4. Cytoredective agents if indicated
55
Treatment regimen for high risk essential thrombocythaemia?
1. Aspirin 2. Cytoredective agents: Hydroxyurea or Peg-IFNα 2A +/- anagrelide 3. Monitor for acquired vWD 4. Monitor for CVS risk factors, new thrombosis, bleeding
56
Treatment regimen for PMF with low risk of AML and predicted long survival
1. Ruxolitinib based on symptoms and organomegaly 2. Cytoreduction: Hydroxyurea or Peg-IFNα 2A 3. Management of anaemia and cytopenia
57
Treatment regimen for PMF with high risk of AML and predicted short survival?
1. Allo-HSCT if transplant eligible **diff. from low risk** 2. Ruxolitinib based on symptoms and organomegaly 3. Cytoreduction: Hydroxyurea or Peg-IFNα 2A 4. Management of anaemia and cytopenia
58
Ddx of genuine erythrocytosis?
Primary = EPO suppressed: - PV Secondary = EPO not suppressed: - Chronic hypoxaemia - Renal condition with increased EPO production - Rare paraneoplastic (RCC,HCC)
59
Ddx of isolated thrombocytosis?
Primary (marrow cause): - MPN (ET) Secondary (reactive) - Bleeding/ Iron deficiency ***common*** - Paraneoplastic phenomena (rare) - Inflammation (rare)
60
Explain why increased aPTT is seen in essential thrombocythaemia?
Isolated thrombocytosis: more platelets = consume more vWB factors = Reduce binding of factor 8 to VWB = Reduce t1/2 of factor 8, less react with thromboplastin = Prolong aPTT
61
Define MDS/MPN? What is the classical type? What are the 3 blood cell abnormality criteria?
Clonal haematological disorders, classic = CMML 1) proliferation in one lineage (typically leucocytosis), 2) cytopenia in ≥1 other lineage(s) (typically anaemia and/or thrombocytopenia) 3) dysplasia in ≥1 lineage
62
CBC finding of CMML?
Classical = chronic myelomonocytic leukaemia (CMML) leucocytosis, monocytosis +/- anaemia +/- thrombocytopenia occasional promonocytes and dysplastic neutrophils
63
Presentation of CMML?
anaemic symptoms and easy brusing Pallor and hepatosplenomegaly.
64
Marrow finding for CMML?
monocytosis dysplastic neutrophils (hypogranular with abnormal lobulation) Hypercellular, dysplastic myeloid series and megakaryocytes
65
Difference in CBC finding of the 2 phases of PMF?
1. Cellular (prefibrotic) phase:  Anaemia  White cell count ↑  Platelet count ↑ 2. Fibrotic phase: pancytopenia