Myeloproliferative Disorders

Question 1

What are myeloproliferative disorders?

Answer 1

Conditions which occur due to uncontrolled proliferation of a single type of stem cell.

Question 2

What are myeloproliferative disorders considered to be?

Answer 2

A type of bone marrow cancer

Question 3

What are the three main myeloproliferative disorders?

Answer 3

• Primary myelofibrosis
• Polycythaemia vera
• Essential thrombocythaemia

Question 4

What is primary myelofibrosis the result of?

Answer 4

The result of proliferation of the hematopoietic stem cells.

Question 5

What is polycythaemia vera the result of?

Answer 5

The result of proliferation of the erythroid cell line.

Question 6

What is essential thrombocythemia the result of?

Answer 6

The result of proliferation of the megakaryocytic cell line.

Question 7

What do Myeloproliferative disorders have the potential to do?

Answer 7

Progress and transform into acute myeloid leukaemia.

Question 8

What gene mutations are these conditions associated with?

Answer 8

• JAK2
• MPL
• CALR

Question 9

What gene mutation do the majority of people with polycythaemia vera have?

Answer 9

JAK2 mutation

Question 10

What is myelofibrosis though to be caused by?

Answer 10

Hyperplasia of abnormal megakaryocytes

Question 11

What can myelofibrosis be the result of?

Answer 11

• Primary myelofibrosis
• Polycythaemia vera
• Essential thrombocythemia.

Question 12

What does the proliferation of the cell line lead to in myelofibrosis?

Answer 12

It leads to fibrosis of the bone marrow.

The bone marrow is replaced by scar tissue.

Question 13

What is fibrosis of the bone marrow the result of?

Answer 13

Cytokines that are released from the proliferating cells.

Especially cytokine- fibroblast growth factor.

Question 14

What does fibrosis of the bone marrow affect?

Answer 14

The production of blood cells and can lead to anaemia and low white blood cells (leukopenia).

Question 15

Where does the production of blood cells start to occur when there is fibrosis of the bone marrow?

Answer 15

Liver and Spleen

Question 16

What is the name of the production of red blood cells in the spleen and liver?

Answer 16

Extramedullary haematopoiesis

Question 17

What can extramedullary haematopoiesis result in?

Answer 17

hepatomegaly and splenomegaly

Question 18

How do myeloproliferative disorders present?

Answer 18

• Fatigue (most common presenting symptom)
• Hypermetabolic symptoms: Weight loss, Night sweats, Fever
• Massive splenomegaly

Question 19

What hypermetabolic symptoms might present with myeloproliferative disorder?

Answer 19

Weight loss
Night sweats
Fever

Question 20

What might you find on a blood film with primary myeloproliferative disorder?

Answer 20

‘tear-drop’ poikilocytes

Question 21

What might you find with a FBC?

Answer 21

• anaemia

* high WBC and platelet count early in the disease

Question 22

What is the management of mild primary myelofibrosis?

Answer 22

Monitored and not actively treated.

Question 23

What is potentially curative for primary myelofibrosis but carries risk?

Answer 23

Allogenic stem cell transplant

Question 24

What is the function of chemotherapy in primary myelofibrosis?

Answer 24

Helps to control the disease, improve symptoms and slow progression but is not curative alone

Question 25

What are 3 key signs of polycythaemia vera?

Answer 25

* Conjunctival plethora (excessive redness to the conjunctiva in the eyes) (red face) * A “ruddy” complexion * Splenomegaly

Question 26

What would you find on a full blood count of someone with polycythaemia vera?

Answer 26

* Raised haemoglobin (more than 185g/l in men or 165g/l in women) * Primary Thrombocythaemia: Raised platelet count (more than 600 x 109/l) * Due to proliferation, raised uric acid

Question 27

What is the first line management of polycythaemia vera?

Answer 27

Venesection

Question 28

What is the function of venesection?

Answer 28

To keep the haemoglobin in the normal range

Question 29

What can be used to reduce the risk of developing clots?

Answer 29

Aspirin

Question 30

What can be used to control the disease of polycythaemia vera?

Answer 30

Chemotherapy

Question 31

What is the definitive diagnostic test for polycythaemia vera?

Answer 31

Bone marrow biopsy

Question 32

How does a bone marrow biopsy present with polycythaemia vera?

Answer 32

Dry- all of the aspiration is usually dry

Question 33

What are the main features of essential thrombocythaemia?

Answer 33

platelet count > 600 * 109/l both thrombosis (venous or arterial) and haemorrhage can be seen a characteristic symptom is a burning sensation in the hands a JAK2 mutation is found in around 50% of patients

Question 34

What does megakaryocyte proliferation lead to?

Answer 34

Overproduction of platelets

Question 35

What is the medical management of Essential thrombocythaemia?

Answer 35

Hydroxycarbamide

Question 35

What is the medical management of essential thrombocythaemia?

Answer 35

Hydroxycarbamide

Question 36

What is the function of Hydroxycarbamide?

Answer 36

Reduce the platelet count