Thrombocytosis

Question 1

essential thrombocytosis

Answer 1

chronic myeloproliferative disorder seen with clonal proliferation of platelets leading to plts >450K

Question 2

what gene mutation is seen with ET?

Answer 2

JAK2 V617F

JAK2 is also seen with polycythemia vera and primary myelofibrosis

Question 3

symptoms of essential thrombocytosis

Answer 3

generally asymptomatic but

can have vasomotor symptoms (headaches, dizziness, chest pain), thrombosis (DVT) and hemorrhage (mucosal bleeding), and see splenomegaly

Question 4

labs of essential thrombocytosis

Answer 4

Hgb and leukocyte count was normal. See elevated platelets>450K

CML must be excluded for ET

DVT, headaches, chest pain and splenomegaly.

Question 5

low risk for thrombosis in essential thrombocytopenia

Answer 5

age<60 and no previous thrombosis

treat with aspirin

Question 6

higher risk for thrombosis in essential thrombocytopenia

Answer 6

age>60 and thrombocytosis

treat with hydroxyurea

Question 7

what is also seen with essential thrombocytosis that is acquired?

Answer 7

acquired von Willebrand dx (20%) develop this and this is due to large consumption of von Willebrand factor multimers secondary to platelet activation and proteolysis.

Question 8

to distinguish between essential thrombocytosis and polycythemia vera is that

Answer 8

essential thrombocytosis will have normal RED BLOOD CELL mass and normal HGB

Question 9

what do you see on labs with essential thrombocytosis and acquired von Willebrand dx?

Answer 9

decreased von willebrand ristocetin cofactor activity and high molecular weight von willebrand factor multimers

Question 10

see headaches and digital pains of the toes and fingers and cumulate in gangrene

see erythromelalgia burning pain and dusky extremities

Answer 10

due to congestion of blood cells

see essential thrombocytosis.

Question 11

if considering essential thrombocytosis what must you also rule out?

Answer 11

rule out other myeloproliferative disorders like CML, polycythemia vera, and primary myelofibrosis and myelodysplastic syndromes.

Will see JAK2 in 50% of pts

must rule out Fe deficiency anemia - can cause primary thrombocytosis.

Question 12

causes of secondary thrombocytosis are:

Answer 12

fe deficiency anemia
infection
inflammation
splenectomy

Question 13

vasomotor symptoms of essential thrombocytosis are:

Answer 13

• headaches, visual disturbances
• dysesthesia of palms and soles
• syncope
• livedo reticularis

Question 14

when are pts with essential thrombocytosis at risk for hemorrhage?

Answer 14

when there’s platelets >1.5 million or use of high dose aspirin

Question 15

why is there a risk for elevated hemorrhage with high platelets?

Answer 15

thought to be due to increased risk for acquired von Willebrand dx.

Question 16

Acquired von willebrand disease is:

Answer 16

a rare bleeding disorder of low von willebrand factor