Myeloproliferative Disorder: Myelofibrosis

Question 1

What causes it?

Answer 1

Hyperplasia of abnormal megakaryocytes - release of platelet derived growth factor is thought to stimulate fibroblasts

Question 2

What does it result in?

Answer 2

Intense bone marrow fibrosis

Haematopoiesis develops in liver and spleen

Question 3

How does it present?

Answer 3

Hyper metabolic symptoms - weight loss, night sweats, fever
Abdominal discomfort - splenomegaly
Bone marrow failure symptoms - infections, bleeding, anaemia - SOB, fatigue

Question 4

Are cytogenetic abnormalities found in the majority?

Answer 4

Yes e.g JAK2 mutation

Question 5

What laboratory findings are present?

Answer 5

Anaemia
High WBC and platelets early in disease (then pancytopenia)
High urate and LDH - increased cell turnover
Tear drop poikiloctyes on blood film
Unobtainable bone marrow biopsy (dry tap) so trephine biopsy needed

Question 6

What are abnormally shaped RBCs called?

Answer 6

Poikilocyte

Question 7

How is it treated?

Answer 7

Marrow support e.g transfusions
JAK2 inhibitors
Splenectomy
Allogenic stem cell transplant