Updated: 1/27/2019

Polycythemia Rubra Vera

Topic
Review Topic
0
0
https://upload.medbullets.com/topic/120246/images/erythromelalgia.jpg
https://upload.medbullets.com/topic/120246/images/polycythemia_vera,_blood_smear.jpg
Snapshot
  • A 63-year-old man presents to urgent care with painful fingers and toes. He complains of a burning sensation, especially in the afternoon when the temperature is highest. He has had similar episodes in the past which resolve on its own. However, today his fingers are particularly painful. On review of systems, he reveals that he is fatigued and experiences night sweats and regular headaches. His weight today is 20 lbs lighter than his previous documented weight. Concerned, his physician orders a complete blood count and serum EPO level, both of which come back abnormal. His hemoglobin is 17 g/dL and his EPO level is well below normal. However, his peripheral blood smear shows RBC precursor cells.
Introduction
  • Myeloproliferative neoplasm with primarily increased production of RBCs
  • Epidemiology
    • presentation in the 60s-70s
    • male and females equally affected
    • potentially more prevalent in those of Ashkenazi Jewish descent
  • Pathogenesis
    • mutations in JAK2 (Janus kinase)
      • V617F mutation
      • constitutively active Janus Kinase unregulated myeloproliferation
    • erythrocytosis ↑ blood viscosity
    • leukocytosis
    • thrombocytosis
  • Associated conditions
    • risk of progression to myelofibrosis or leukemia
Presentation
  • Symptoms
    • highly viscous blood
      • headaches
      • visual disturbance
      • thrombosiserythromelalgia (rare but classic)
        • painful burning sensation with increased temperatures in digits
        • episodic blood clots in extremities
      • hypertension
    • bleeding from engorged vessels
    • constitutional symptoms
      • fatigue
      • night sweats
      • weight loss
      • fever
      • malaise
    • pruritus exacerbated by hot water
      • histamine release from increased basophils
    • gouty attacks
  • Physical exam
    • hepatosplenomegaly
    • bruising
    • ischemic digits
    • large retinal veins on funduscopy
Evaluation
  • Complete blood count with smear
    • ↑ hemoglobin > 16 g/dL (female) or > 16.5 g/dL (male)
    • ↑ hct > 48% (female) or > 49% (male)
  • Bone marrow biopsy with hypercellularity
    • prominent proliferation of all cell lines
      • commonly seen with precursor cells
    • confirms diagnosis
    • baseline for assessing disease progression
  • JAK2 mutation in peripheral blood – most accurate
  • ↓ serum EPO
    • ↑ RBC despite low EPO
  • ↓ MCV
  • SaO2 normal
 
 
SaO2
EPO
RBC mass
Plasma Volume
Hypoxemia
Normal
Polycythemia rubra vera
Normal
Ectopic erythopoeitin
Normal
Normal
Smokers polycythemia
Variable
Stress polycythemia
Normal
Normal
Normal
Dehydration
Normal
Normal
Normal

Differential Diagnosis
  • Secondary polycythemia
  • Tumor-driven polycythemia
  • Other myeloproliferative neoplasm
Treatment
  • For low risk patients (< 60 years old and no prior thrombosis)
    • low-dose aspirin
      • to prevent thrombosis
    • perform phlebotomy until hematocrit is < 45%
  • For high risk patients ( 60 years old and/or prior thrombosis)
    • all the above plus
      • hydroxyurea (decrease cell count)
      • INF-α
    • second-line
      • ruxolitinib (JAK inhibitor)
  • Gout prophylaxis
    • allopurinol  
  • Pruritus      
    • antihistamines
Prognosis, Prevention, and Complications
  • Prognosis
    • > 10 years with treatment
    • 1.6x higher mortality than general population
  • Complications
    • thrombosis
      • leading cause of morbidity and mortality
      • 45% of all deaths in polycythemia vera
      • Budd-Chiari syndrome
        • occlusion of IVC or hepatic veins leading to congestive liver disease
    • hemorrhage
    • peptic ulcers
      • increased histamine release from basophils
    • gout
    • progression to
      • myelofibrosis
      • CML
      • AML
 

Please rate topic.

Average 5.0 of 2 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Topic COMMENTS (2)
Private Note