Myeloproliferative Neoplasms/Disorders Flashcards
What are MPNs?
rapid growth of granulocytes, red cells and platelets
maturation is preserved
How do MPNs present on investigation?
high granulocyte count high red cell count/Hb high platelet count eosinophilia/basophilia splenomegaly thrombosis in unusual places
What are examples of MPNs?
Chronic myloid leukaemia
Polycythaemia Vera
Myelofibrosis
essential thrombocythaemia
What diferentiates MPNs?
BCR-ABL 1 gene
What MPNs are BCR-ABL 1 gene positive?
CML
What MPNs are BCR-ABL 1 gene negative?
Polycythaemia Vera
Myelofibrosis
essential thrombocythaemia
What is PV?
high Hb/Hct accompanied by erythrocytosis but can also have excessive production of other lineages
How does PV present?
headache
fatigue
itch
increased blood viscosity
What is a common mutation found in PV? What does it cause?
JAK 2 - leads to loss of auto inhibition and activation of erythropoesis in the absence of a ligand
How is PV treated?
venesect to Hct <0.45
aspirin
cytotoxic oral chemo
What are differentials of PV?
secondary polycythaemia - chronic hypoxia, smoking, EPO secreting tumours
pseudopolycythaemia - dehydration, diuretic therapy, obesity
What is essential thrombocythaemia?
uncontrolled proliferation of abnormal platelets
How does essential thrombocythaemia present?
bleeding and classical MPN features
What are the genetics behind essential thrombocythaemia?
20% of pts will have triple negative - JAK2, CALR, MPL
How is essential thrombocythaemia treated?
antiplatelets - aspirin
cytoreductive therapy to control proliferation - hydroxycarbamide, interferon alpha
What is Myelofibrosis?
MPN that causes extensive scarring in the bone marrow
What are the 3 types of myelofibrosis?
idiopathic
post polycythaemia
essential thrombocythaemia
How does myelofibrosis present?
marrow failure
splenomegaly
hypercatabolism
What does myelofibrosis look like on blood film?
tear drop shaped RBCs and leucoerythroblastic picture
What is a leucoerythroblastic film?
presence of immature erythrocytic and neutrophilic precursors in the peripheral blood
What can cause a leucoerythroblastic film?
reactive - sepsis marrow infiltration lymphoma severe bleeding shock myelofibrosis
How is myelofibrosis treated?
supportive - blood transfusion, platelets, antibodies
allogenic stem cell transplant
JAK2 inhibitors
splenectomy
What can a splenectomy treat?
ITP and AIHA
What must you vaccinate against if you give a splenectomy?
meningococcus
H. influenzae type B
penumococcus
