Polycythemia Vera

Epidemiology

xxx

Etiology

xxx

Physiology

xxx

Diagnosis

Complete Blood Count (CBC) (see Complete Blood Count)

Hemoglobin
- Hemoglobin >16.5 g/dL: defined as polycythemia in males
- Hemoglobin >16.0 g/dL: defined as polycythemia in females
Hematocrit
- Hematocrit >49%: defined as polycythemia in males
- Hematocrit >48%: defined as polycythemia in females
Red Blood Cell Count: not used as often as hemoglobin and hematocrit in the diagnosis of polycythemia (since diseases such as thalassemia minor may have an elevated red blood cell count with a decreased hemoglobin or hematocrit due to an increased number of small/microcytic, poorly hemoglobinized/hypochromic red blood cells)

Serum Erythropoietin (see Serum Erythropoietin)

Decreased Serum Erythropoietin Level: occurs in 81% of cases (Leukemia, 2013) [MEDLINE]

Endogenous Erythroid Colony Formation In Vitro Assay

Endogenous Erythroid Colony Formation Occurs in 73% of Cases (Leukemia, 2013) [MEDLINE]
Technique: performed using in vitro culture technique (available only in specialized centers)
- Formation of Erythroid Colonies in the Absence of Exogenous Erythropoietin

Clinical Manifestations

Cardiovascular Manifestations

Hypertension (see Hypertension)
- Epidemiology: occurs in 46% of cases (Leukemia, 2013) [MEDLINE]
- Clinical: xxxx

Dermatologic Manifestations

Erythromelalgia (see Erythromelalgia)
- Epidemiology: occurs in 29% of cases (Leukemia, 2013) [MEDLINE]
- Clinical: burning pain in hands/feet with associated erythema/pallor/cynanosis
Facial Plethora (Ruddy Cyanosis)
Pruritus (see Pruritus)
- Epidemiology: occurs in 36% of cases (Leukemia, 2013) [MEDLINE]
- Possible Physiologic Mechanisms
  - Mast Cell Degranulation: with release of histamine, fibrinolytic factors, prostaglandins, and/or IL-31)
  - Release of Adenosine Disphosphate from Red Blood Cells or Release of Catecholamines from Adrenergic Vasoconstrictor Nerves When the Skin is Cooled: resulting in platelet aggregation in the skin blood vessels with local production of prostaglandins (which cause pruritus)
- Clinical
  - Aquagenic Pruritus (Pruritus Following a Warm Bath/Shower): common (and may be present for years prior to the formal diagnosis of polycythemia vera)
  - Excoriation of the Skin May Be Seen in Association with the Pruritus
- Treatment: aspirin may be effective in some cases

Gastrointestinal Manifestations

Gastroduodenal Erosions/Peptic Ulcer Disease (PUD) (see Peptic Ulcer Disease)
- Epidemiology: occurs in some cases
- Physiology: alteration in gastric mucosal blood flow (due to altered blood viscosity, release of histamine from tissue basophils, and/or Helicobacter Pylori infection)
Hepatomegaly (see Hepatomegaly)
- Epidemiology: occurs in some cases

Hematologic Manifestations

Abnormal Karyotype
- Epidemiology: occurs in 12% of cases (Leukemia, 2013) [MEDLINE]
Decreased Serum Erythropoietin Level
- Epidemiology: occurs in 81% of cases (Leukemia, 2013) [MEDLINE]
Elevated Serum Lactate Dehydrogenase (LDH) (see Elevated Serum Lactate Dehydrogenase, Elevated Serum Lactate Dehydrogenase)
- Epidemiology: occurs in 50% of cases (Leukemia, 2013) [MEDLINE]
Endogenous Erythroid Colony Formation
- Epidemiology: occurs in 73% of cases (Leukemia, 2013) [MEDLINE]
- Diagnosis: performed using in vitro culture technique (available only in specialized centers) -> formation of erythroid colonies in the absence of exogenous erythropoietin
Hemorrhage
- Epidemiology: major hemorrhage occurs in 4% of cases (Leukemia, 2013) [MEDLINE]
Hypercoagulable State (see Hypercoagulable States, Hypercoagulable States)
- Arterial Thrombosis: occurs in 16% of cases (Leukemia, 2013) [MEDLINE]
  - Acute Limb Ischemia (see Acute Limb Ischemia, Acute Limb Ischemia)
  - Acute Myocardial Infarction (MI) (see Coronary Artery Disease, Coronary Artery Disease)
  - Ischemic Cerebrovascular Accident (CVA) (see Ischemic Cerebrovascular Accident, Ischemic Cerebrovascular Accident)
- Venous Thrombosis: occurs in 7% of cases (Leukemia, 2013) [MEDLINE]
  - Cerebral Venous Thrombosis (see Cerebral Venous Thrombosis, Cerebral Venous Thrombosis)
  - Deep Venous Thrombosis (DVT) (see Deep Venous Thrombosis, Deep Venous Thrombosis)
  - Hepatic Vein Thrombosis (Budd-Chiari Syndrome) (see Hepatic Vein Thrombosis, Hepatic Vein Thrombosis)
  - Mesenteric Vein Thrombosis (see Mesenteric Vein Thrombosis, Mesenteric Vein Thrombosis)
  - Superficial Thrombophlebitis (see Superficial Venous Thrombosis, Superficial Venous Thrombosis)
Leukoerythroblastic Smear
- Epidemiology: occurs in 6% of cases (Leukemia, 2013) [MEDLINE]
Leukopenia/Leukocytosis (see Leukopenia, Leukopenia and Leukocytosis, Leukocytosis)
- Clinical: median 10,400 per μL, range 3000-172,000 per μL (Leukemia, 2013) [MEDLINE]
Polycythemia (see Polycythemia, Polycythemia)
- Clinical
  - Elevated Hemoglobin: median 18.4 g/dL, range 15.1-26.5 g/dL (Leukemia, 2013) [MEDLINE]
  - Elevated Hematocrit: median 55%, range 36-78% (Leukemia, 2013) [MEDLINE]
  - Elevated Red Blood Cell Count
Positive JAK2 Mutation
- Epidemiology: occurs in 98% of cases (Leukemia, 2013) [MEDLINE]
Splenomegaly (see Splenomegaly, Splenomegaly)
- Epidemiology: occurs in 36% of cases (Leukemia, 2013) [MEDLINE]
Thrombocytopenia/Thrombocytosis (see Thrombocytopenia, Thrombocytopenia and Thrombocytosis, Thrombocytosis)
- Clinical: median 466,000 per μL, range 70,000-2,370,000 per μL (Leukemia, 2013) [MEDLINE]

Ophthlamologic Manifestations

Conjunctival Injection (see xxxx, xxxx)
Engorgement of Veins of Optic Fundus
Transient Visual Disturbances
- Ophthlamic Migraine (see Migraines, Migraines)
- Scintillating Scotoma
- Transient Ocular Blindness (Amaurosis Fugax) (see Amaurosis Fugax, Amaurosis Fugax)

Pulmonary Manifestations

Pulmonary Hypertension (Group 5) (see Pulmonary Hypertension, Pulmonary Hypertension)
- Physiology: xxx

Rheumatologic/Orthopedic Manifestations

Gouty Arthritis/Tophi (see Gout, Gout)

Treatment

Ruxolitinib (Jakafi) (see Ruxolitinib, Ruxolitinib)

xxxx

References

Survival and prognosis among 1545 patients with contemporary polycythemia vera: an international study. Leukemia. 2013;27(9):1874. Epub 2013 Jun 6 [MEDLINE]