Essay 10- MPN. Essential thrombocythaemia and myelofibrosis
Essential thrombocythaemia
Primary myelofibrosis
Essay 10- MPN. Essential thrombocythaemia and myelofibrosis
What are MPNs?
The abnormal proliferation of one or more terminal myeloid cell lines in the peripheral blood gives rise to a heterogeneous group of disorders called myeloproliferative neoplasms:
Chronic myeloid leukemia
Polycythaemia vera
Essential thrombocythaemia
Primary myelofibrosis
Essential thrombocythaemia
Definition
Condition in which there is a sustained increase in the platelet count due to megakaryocyte proliferation and overproduction!
Etiology
Overproduction of hematopoietic cells due to the mutations of the JAK2, CALR, or MPL genes
Most have JAK-2
Symptoms
Various levels of thrombosis (hepatic vein thrombosis)
Headache
Visual changes
Fatigue
Burning sensation felt in the hands or feet and promptly relieved by aspirin
Insomnia
Migraines
Dizziness
TIA
Erythromegalia
Easy bruising
Diagnosis
The suggested diagnostic criteria are:
A1- Sustained platelet count above 450 × 109/L.
A2- Presence of an acquired pathogenetic mutation (e.g. in JAK2 or CALR).
A3- No other myeloid malignancy, PV, primary myelofibrosis, chronic myeloid leukaemia (CML) or myelodysplastic syndrome.
A4- No reactive cause for thrombocytosis and normal iron stores.
A5- Bone marrow trephine histology showing increased megakaryocytes with prominent large hyperlobulated forms; reticulin is generally not increased.
Diagnosis requiresA1–A3 or A1 + A3–A5!
Blood film- abnormally large platelets and megakaryocyte fragments
Bone marrow- similar to PV but there is an excess of abnormal megakaryocytes!
Testing for genetic mutation
Treatment
Principle is to reduce risk of major clinical problems of thrombosis or hemorrhage
Identify CV risk factors and treat them (cholesterol, smoking, obesity, HTN
Low dose aspirin in all cases!
High risk patients- treat with hydroxycarbamide or anagrelide to reduce platelet count
Over 60
With previous thrombosis
Platelet count greater than 1500
Hydroxycarbamide is the most widely used treatment and is well tolerated
Side effects (prolonged therapy)- skin keratosis, epitheliomas, ulceration, pigmentation
Anagrelide is a good second‐line treatment but has cardiovascular side‐effects
Continue reading free
The whole note, all 3 sections, is free with an AceMed account, with its 1 flashcard. Premium adds flashcard recall, highlights and Ask AI.
