Myeloproliferative disorders Flashcards
What is Myeloproliferative?
Overproduction of cells in the bone marrow
There are four main myeloproliferative disorders. What are they?
Chronic myelogenous leukemia (CML)
Polycythemia vera
Myelofibrosis
Essential thrombocytosis
What is polycythemia vera is characterized by what?
2
elevated Hgb/HCT.
Elevated red cell mass (although difficult to measure)
Elevated hemoglobin and hematocrit
There are 3 main causes of polycythemia in general. (elevated HgB and HCT)
What are they?
Appropriately elevated erythropoietin: hypoxemia
Inappropriately elevated erythropoietin: renal cell carcinoma, hepatocellular carcinoma
Germline and somatic mutation: polycythemia vera
Genetic production
Renal production
something wrong with erythropoeitn production
Survival if untreated?
treated?
untreated is 6-18 months
If treated the survival is > 10 years
Symptoms associated with polycythemia?
Headache
Weakness
Dizziness
Excessive sweating
Demigraphic that usually gets polycythemia?
3
Average age at diagnosis is 60 years of age
Men more common then women
Most common is in men aged 70-79 (24 cases per 100,000)
Hallmark symptoms of polycythemia?
2
Pruritus post bathing is a hallmark symptom
Erythromelalgia: burning pain in the feet and/or hands often with pallor, erythema or cyanosis
These with all the symtpoms described before
What are the symptoms of polycythemia related to?
thrombosis
Arterial and venous
Transient visual disturbances assocaited with thrombosis due to polycythemia?
2
Amaurosis fugax Scintillating scotomata (opthlamic migraine, decreased retinal and choroidal blood flow due to increased blood viscosity
GI symtpoms associated with polycythemia?
3
Epigastric discomfort
History of peptic ulcer disease
Gastroduodenal erosions
Physical exam findings in polycythemia vera?
6
- 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
Lab abnormalities in polycythemia vera?
9
- Hgb/HCT > 18.5/56 men
- Hgb/HCT > 16.5/50 women
- WBC > 10.5
- Platelets > 450 K
- Elevated serum lactate dehydrogenase (LDH is released when cells or tissue is destroyed) in 50%
- JAK2 mutation in 98%
- Abnormal serum erythropoietin in 81% (abnormally low)
- Hypercellular bone marrow
- Iron storage in bone marrow is absent
Criteria for PV?
2
Hemoglobin > 18.5 g/dL in men and 16.5 g/dL
Jak2 mutation
What is polycythemia vera treatment targeted at?
2
In which ways can we do this?
3
Lowering hemocrit and decreasing thrombosis
Phlebotomy to keep HCT
What are the mylosuppressive agents that can be used in the treatment of polycythemia vera and in what situations are they used?
1 . Hydroxyurea- use if other treatments arent working or if at high risk for thrombosis
2. Interferon alpha- Use in womenin childbearing age or in hydroxyurea is ineffeective
What are the symptoms of PV?
Pruitis
Hyperuricemia
Erythromelalgia
How would we treat pruitis caused by PV?
7
- Antihistamines,
- H2 blockers,
- myelosuppression,
- interferon alpha,
- antidepressants such as paroxetine (Paxil) or fluoxetine (Prozac),
- photo chemotherapy
- (cool water. hotter the water the worse it will be)
How would we treat hyperuricemia (gout) caused by PV?
Allopurinol for prevention
How would we treat erythromelalgia caused by PV?
2
- Aspirin 75-100 mg daily
2. Lowering the platelet count with myelosuppresive agents also helps
Polycythemia vera can progress to more serious disorders of bone marrow metabolism such as?
2
Myelofibrosis
Acute leukemia
What is the pathology behind myelofibrosis?
What causes it?
Replacement of the marrow with collagenous connective tissue
Cause is generally unknown but it is associated with spent phase of polycythemia
What are the main causes of morbidity and mortality in myelofibrosis?
5
Progression to acute leukemia Infection Bleeding Portal hypertension Vascular complications
What are the most common clinical presentations of myelofibrosis? 2
What are other common manifestations seen in myelofibrosis? 5
severe fatigue
LUQ pain
(due to splenomegaly)
- Symptoms due to splenomegaly (25-50%)
- -LUQ pain (could radiate to left shoulder)
- -Early satiety (gastric vessels plugged up) - Hepatomegaly
- Weight loss (5-20%)
- Low grade fever, night sweats (5-20%)
- Asymptomatic (15-30%)
What are symptoms of myelofibrosis due to hepatomegaly?
5
- Ascites,
- esophageal and gastric varices,
- GI bleeding,
- hepatic encephalopathy,
- portal vein thrombosis
What is extramedullary hemotopoiesis and why is it problematic?
When red cell production is pushed outside the bone marrow and into the surrounding tissue by the medullary tissue turning into connective tissue. It will then disrupt the tissue of that organ that it invades.
What can extramedullary hematopoiesis present as?
(where does it go commonly)
9
- splenomegaly,
- hepatomegaly,
- lymphadenopathy,
- pleural effusions,
- pericardial effusions,
- abdominal effusions,
- GI,
- GU (dysuria) or
- Respiratory (dyspnea)
What will a blood smear look like in someone with myelofibrosis?
2
- Marked poikilocytosis (variation in cell shape)
- Especially with the tear-drop poikilocytes - Anisocytosis
What will a bone marrow biopsy in the early stages of PMF result in?
2
What happens has the disease progresses?
- high white count with a left shift, and a
- hypercellular marrow,
- - features common to all myeloproliferative disorders
the marrow becomes replaced by fibrous tissue.
In PMF what will the WBC look like?
WBC can be low or high
> 30,000 in 11%; or low in 8%
(depending on stage of disease)
In PMF what will platelet levels look like?
Platelets can be low or high
> 500,000 in 13%; or low in 26%
(depending on stage of the disease)
What lab levels will be elevated in PMF?
4
Elevated alkaline phosphatase
Elevated lactate dehydrogenase
Elevated uric acid
Vitamin B12
Why is alkaline phophatase elevated in PMF?
Due to liver involvement or bone disease
Why is lactate dehydrogenase Elevated in PMF?
Due to ineffective hematopoiesis
Why is uric acid elevated in PMF?
Due to enhanced turnover of hematopoietic tissue
Why is B12 elevated in PMF?
Due to increased neutrophil mass
PMF pts might have a JAK2 mutation. What would this disrupt?
regulation of the production of cells in the bone marrow
Characteristics of PMF that you need to know???
4
- bone marrow fibrosis
- philadelphia chromosome absence
- Splenomegaly
- Tear drop erythrocytes
Treatment options for PMF?
6
Pretty limited
- Stem cell transplant
- Hydroxyurea
- Various chemotherapeutic agents
- JAK2 inhibitors:Ruxolitinib (Jakafi)
- Splenectomy but may cause worsening hepatomegaly and decline in liver function
- Radiation therapy (spleen or other sites of EMH)- not to bone marrow but to the sites of extramedullary hematopoeisis
What is essential thrombocytosis due to?
2
- overproduction of platelets
(isolated thrombocytosis)- clotting disorder - Abnormal platelet function that can lead to thrombosis and bleeding- bleeding disorder
How would we diagnose essential thrombocytosis?
elevated platelet count without other blood cell abnormalitites
What would a peripheral smear show in a patient with essential thrombocytosis?
normal RBC morphology
What would a bone marrow biopsy show in essential thrombcytosis?
reveals increase in number and giant megakaryocytes (platelets) but it otherwise normal
HIGH FREQUENCY OF JACK MUTATIONS
STATEMENT
Symptoms are secondary to elevated platelet count in essential thrombocytosis?
6
- Headache
- Lightheadedness
- Visual changes
- Numbness, tingling or burning in the feet (erythromelalgia)
- Splenomegaly
- History of thrombosis
Where is arterial thrombosis most likely to occur?
3
in the hands, feet and brain but can occur anywhere (heart, larger vessels)
Where is venous thrombosis most likely to occur?
4
mesenteric, hepatic and portal vein as well as deep vein thrombosis can occur
What is the treatment targeted at for essential thrombocytosis?
And what are the treatments?
2
lowering the platelet count to prevent symptoms and thrombosis.
- Low dose aspirin (81 mg/day)
- Hydroxyurea to keep platelet count below 500,000
How can essential thrombocytosis progress to worse conditions?
4
Bone marrow may become fibrotic
Massive splenomegaly may occur
10-15% risk of progression to myelofibrosis after 15 years
1-2% risk of progression to acute myelogenous leukemia over 20 years