Myeloproliferative Disease

Question 1

What are myeloproliferative disorders?

Answer 1

• Myeloproliferative disorders involve the uncontrolled proliferation of a single type of stem cell.
• They are considered a form of cancer occurring in the bone marrow, although they tend to develop and progress slowly.

Question 2

What have myeloproliferative disorders got the potential to transform into?

Answer 2

AML

Question 3

What are the 3 main myeloproliferative disorders?

Answer 3

• Primary myelofibrosis
• Polycythaemia vera
• Essential thrombocythaemia

Question 4

What is the proliferating cell line in primary myelofibrosis?

Answer 4

Haematopoietic stem cells

Question 5

What are the blood findings in primary myelofibrosis? (3)

Answer 5

Low haemoglobin
High or low white cell count
High or low platelet count

Question 6

What is the proliferating cell line in polycythemia Vera?

Answer 6

Erythroid cells

Question 7

What are the blood findings in polycythemia Vera?

Answer 7

High Hb

Question 8

What is the proliferating cell line in essential thrombocytopenia?

Answer 8

Megakaryocytes

Question 9

What is the blood findings in essential thrombocytopenia?

Answer 9

High platelet counts

Question 10

Which genes are commonly mutated in myeloproliferative disorders? (3)

Answer 10

• JAK2
• MPL
• CALR

Question 11

What is myelofibrosis?

Answer 11

• Myelofibrosis is where the proliferation of a single cell line leads to bone marrow fibrosis, where bone marrow is replaced by scar tissue.
• This is in response to cytokines released from the proliferating cells.
• One particular cytokine is fibroblast growth factor.

Question 12

What does myelofibrosis lead to?

Answer 12

Pancytopenia

Question 13

In myelofibrosis haematopoiesis starts happening other places. Where and what signs does this cause? (3)

Answer 13

Liver - hepatomegaly portal hypertension
Spleen - splenomegaly
Around the spine - spinal cord compression

Question 14

What is shown on a blood film in myelofibrosis? (3)

Answer 14

○ Teardrop-shaped red blood cells
○ Anisocytosis (varying sizes of red blood cells)
○ Blasts (immature red and white cells)

Question 15

What are the non-specific symptoms of myeloproliferative disorders? (4)

Answer 15

• Fatigue
• Weight loss
• Night sweats
• Fever

Question 16

What are the clinical signs of polycythemia? (4)

Answer 16

• Ruddy complexion (red face)
• Conjunctival plethora (the opposite of conjunctival pallor)
• Splenomegaly
• Hypertension

Question 17

What is the diagnostic investigation in myeloproliferative disorders?

Answer 17

Bone marrow biopsy

Question 18

What is the bone marrow biopsy finding in myelofibrosis?

Answer 18

Aspiration is dry as bone marrow has turned to scar tissue

Question 19

What is the management for myelofibrosis? (5)

Answer 19

• No active treatment for mild disease with minimal symptoms
• Supportive management of complications, such as anaemia, splenomegaly and portal hypertension
• Chemotherapy (e.g., hydroxycarbamide) to help control the disease
• Targeted therapies, such as JAK2 inhibitors (ruxolitinib)
Allogeneic stem cell transplantation (risky but potentially curat

Question 20

What is the management of polycythemia Vera? (3)

Answer 20

• Venesection to keep the haemoglobin in the normal range
• Aspirin to reduce the risk of thrombus formation
• Chemotherapy (typically hydroxycarbamide) to help control the disease

Question 21

What is the management of essential thrombocytopenia? (3)

Answer 21

• Aspirin to reduce the risk of thrombus formation
• Chemotherapy (typically hydroxycarbamide) to help control the disease
• Anagrelide is a specialist platelet-lowering agent