Haem - myeloproliferative disorders

Question 1

Which population tends to be affected by myeloproliferative disorders

Answer 1

Elderly

Question 2

Why do myelproliferative disorders precipitate attacks of gout

Answer 2

Rapid cell turnover –> increased purine metabolism –> raised uric acid levels –> precipitate attacks of gout

Question 3

What is relative polycythemia

Answer 3

Decrease in plasma volume leads to raised haematocrit giving the impression of increased RBCs

Question 4

What is primary polycythaemia vera(PV)

Answer 4

Due to mutation in erythrocyte receptor(JAK-2) leading to increased RBCs

There will be low EPO due to negative feedback

Question 5

What is secondary abnormal PV due to

Answer 5

EPO secreting tumour(RCC, HCC, phaeo)

Question 6

What is secondary compensatory PV due to

Answer 6

Response to hypoxia

• COPD
• OSA
• High altitude
• CO poisoning
• Right to left cardiac shunt

Question 7

Which syndrome can PV lead to

Answer 7

Hyperviscosity syndrome

Question 8

Features of hyper viscosity syndrome

Answer 8

Tortuous retinal veins –> visual disturbance

Headaches
Dizziness
Tinnitus
Bleeding

Question 9

Clinical features of PV

Answer 9

Easy bruising and bleeding due to thrombocytosis(sucky platelets)

Erythromelalgia

Aquatic pruritus

Gout

Hepatosplenomegaly

Question 10

What is aquatic pruritus

Answer 10

Itching after hot shower(histamine release)

Question 11

What is erythromelalgia

Answer 11

Paroxysmal dilation of small arteries in the feet and hands –> swelling, erythema and burning pain

Microvascular thromboses(due to increased number of platelets)

Question 12

IX for PV

Answer 12

Increased Hb
Increased Hct, RBC count, Plt

Bone marrow biopsy - generalised hypercellularity, absence of bone marrow iron

EPO levels low

ABG - to rule out hypoxia as cause

JAK2 mutation test

Question 13

Complications of PV

Answer 13

Budd-chiari syndrome
MI
Stroke

Question 14

Treatment of PV

Answer 14

Phelbotomy(to reduce rbc count) 
Myelosuppressant(hydroxyurea) 
Aspirin(erythromelalgia and thromboses) 
Antihistamine(for aquagenic pruritus) 
Allopurinol(to decrease uric acid)

Question 15

Presentation of essential thrombocytosis

Answer 15

Bruising 
Bleeding 
Erythromelalgia 
Headache and visual disturbance
Gout 
Hepato-splenomegaly(rare in ET)

Question 16

Diagnosis of ET

Answer 16

FBC - Plt
Peripheral smear
Bone marrow biopsy –> megakaryocytic hypertrophy and hyperplasia
JAK-2 kinase mutation test

Question 17

Causes of secondary thrombocytosis

Answer 17

Iron deficiency 
Infection 
Inflammation 
Splenectomy 
Trauma 
Surgery 
Ischaemia

Question 18

Management of ET

Answer 18

Hydroxyurea(reduce PLT)
Anegralide, pegylated interferon(reduce PLT)
Aspirin(anti-platelet - treatment of erythromelalgia)

Question 19

What is anegralide

Answer 19

PDE inhibitor which blocks maturation of megakaryocytes into platelets

Question 20

What is primary myelofibrosis

Answer 20

Clonal malignancy where there is atypical megakaryocytes –> monoclonal proliferation of fibroblasts

Question 21

Ix - Primary myelofibrosis

Answer 21

Early panmyelosis - nucleated RBCs, pro-myelocytes, myeloblasts

Increased uric acid, LDH and ALP

X-ray - osteosclerosis

Question 22

Clinical findings in primary myelofibrosis

Answer 22

Tear drop cells 
Anaemia symptoms 
Infections if leukopenia 
Pancytopenia 
Gout

Question 23

Bone marrow aspiration - Primary myelofibrosis

Answer 23

‘Inaspirable marrow’

Increased reticulin

Question 24

Treatment of primary myelofibrosis

Answer 24

Splenectomy 
Steroids --> inhibit fibroblasts 
Allopurinol(for gout) 
Chemotherapy 
Allogenic bone marrow transplant

Question 25

Complications of primary myelofibrosis

Answer 25

Pancytopenia

Malignant transformation –> AML

Question 26

Causes of secondary myelofibrosis

Answer 26

P vera

ET

Question 27

Causes of secondary myelofibrosis

Answer 27

P Vera
ET
Metastasis to the bone marrow from other tumours

Question 28

Effect of steroids on neutrophil count

Answer 28

Cause neutrophilia