Session 5- myeloproliferative neoplasms

Question 1

What is a myeloproliferative neoplasm?

Answer 1

Disease where excess cells are produced from the bone marrow

Question 2

What is polycythaemia?

What are common symptoms?

Answer 2

Haematocrit exceeds 52% males / 48% females
Absolute - excess RBC’s
Relative- less plasma

(due to thicker blood)

• headache
• thrombosis
• burning pain in hands/ feet (erythromelalgia)

Question 3

What causes polycythemia vera?

Answer 3

mutation in the gene coding for Janus Kinase 2 (JAK2) in haematopoietic stem cells of the bone marrow. These cells survive longer and are constantly dividing to produce erythrocytes

Question 4

How do you treat severe polycythemia?

Answer 4

(risk of clotting)
give hydroxycarbamide which reduces your blood cell and platelet count ‘debulking the blood’

(can give aspirin for mild cases)

Question 5

What causes secondary polycythemia?

Answer 5

increased stimulation by erythropoietin

• chronic hypoxia so more EPO
• EPO secreting tumour

Question 6

Which cells are platelets formed from?

Answer 6

megakaryocytes

Question 7

What is redistributional thrombocytosis?

Answer 7

Excess platelets in the blood due to redistribution from the splenic pool into the blood

Question 8

What is immune thrombocytopenic purpura? (ITP)

How do you treat it?

Answer 8

Autoimmune condition against platelets
(purpura links to purpuric rash due to tiny haemorrhages)
immunosuppressive drugs like corticosteroids

Can be associated with other autoimmue conditions like arthritis or lupus

Question 9

How does primary myelofibrosis cause extramedullary haemopoiesis?

Answer 9

Mutated progenitor cells can migrate to and colonise the liver and spleen
(poor outcome)

Question 10

What happens in chronic myeloid leukaemia?

Answer 10

Mature granulocytes in the bone marrow proliferate unregulated causing too many granulocytes in the blood

Question 11

Which genetic mutation causes chronic myeloid leukaemia?

How do you treat CML?

Answer 11

chromosomal translocation between 9 and 22 to create the Philadelphia Chromosome

Tyrosine kinase inhibitors

Question 12

How do acute and chronic myeloid leukaemias differ?

Answer 12

Acute causes bone marrow failure quickly because its overwhelmed with a large number of immature blast
cells
Chronic is slow to develop and involves proliferation of mature granulocytes

Question 13

What is aplastic anaemia?

Answer 13

Disease of the bone marrow leading to pancytopenia