Myeloproliferative Disorders

Question 1

Polycythemia vera

Answer 1

mainly characterized by an elevated Hgb/HCT
Elevated red cell mass (although difficult to measure)
Elevated hemoglobin and hematocrit

Question 2

There are 3 main causes of polycythemia in general.

Answer 2

Appropriately elevated erythropoietin: hypoxemia

Inappropriately elevated erythropoietin: renal cell carcinoma, hepatocellular carcinoma

Germline and somatic mutation: polycythemia vera

Question 3

Polycythemia vera symptoms

Answer 3

Headache
Weakness
Dizziness
Excessive sweating
Pruritus post bathing is a hallmark symptom
Erythromelalgia: burning pain in the feet and/or hands often with pallor, erythema or cyanosis

Question 4

Lab abnormalities Polycythemia vera symptoms

Answer 4

Lab abnormalities include polycythemia, thrombocytosis, leukocytosis and others

Hgb/HCT  > 18.5/56 men
Hgb/HCT > 16.5/50 women
WBC > 10.5
Platelets > 450 K
Elevated serum LDH in 50%
JAK2 mutation in 98%
Abnormal serum erythropoietin in 81%
Hypercellular bone marrow
Iron storage in bone marrow is absent

Question 5

Physical exam findings in Polycythemia vera

Answer 5

findings in polycythemia vera include splenomegaly 70% of the time.
Facial plethora (ruddy cyanosis) 67%
Hepatomegaly
Injection of conjunctival small vessels &/or engorged veins of the optic fundus
Excoriation of the skin
Gouty arthritis and tophi

Question 6

Polycythemia Vera treatment

Answer 6

targeted at lowering the HCT and decreasing thrombosis.
Phlebotomy to keep HCT < 45 men; < 42 women
Low dose aspirin 75-100 mg
Myelosuppresive agents:
Hydroxyurea (high risk for thrombosis)
Interferon alpha (women)

Question 7

primary myelofibrosis

Answer 7

Replacement of the marrow with collagenous connective tissue fibers

Unknown etiology and risk factors
It can occur in the spent phase of Polycythemia vera

Question 8

Clinical manifestations of Myelofibrosis

Answer 8

most commonly includes severe fatigue and LUQ pain.

Severe fatigue (50-70%)
Symptoms due to splenomegaly (25-50%)
  LUQ pain
  Early satiety
Weight loss (5-20%)
Low grade fever, night sweats (5-20%)
Asymptomatic (15-30%)

Splenomegaly (90%)
Hepatomegaly (40-70%)

Question 9

Treatment options for PMF

Answer 9

Stem cell transplant
Hydroxyurea
Various chemotherapeutic agents
JAK2 inhibitors: ruxolitinib (Jakafi) $9K/month
Splenectomy-depends
Radiation therapy (spleen or other sites of EMH)

Question 10

Essential Thrombocytosis

Answer 10

Uncommon myeloproliferative condition in which there is isolated thrombocytosis

Abnormal platelet function that can lead to thrombosis and bleeding

Occurs most frequently over the age of 50 and is more common in women

Question 11

Essential Thrombocytosis Symptoms

Answer 11

Headache
Lightheadedness
Visual changes
Numbness, tingling or burning in the feet 
Splenomegaly
History of thrombosis

Question 12

Essential Thrombocytosis Treatment

Answer 12

Low dose aspirin (81 mg/day)

Hydroxyurea to keep platelet count below 500,000