History
Polycythemia vera (PV) frequently comes to the attention of clinicians because of an elevated hematocrit level found on routine laboratory testing. Some patients are asymptomatic, whereas others have various nonspecific symptoms that are recognized in the context of polycythemia vera. Thirty percent of patients report headache, weakness, dizziness, and sweating (in order of decreasing frequency). Many of these symptoms can be attributed to excess hematocrit.
Alternatively, the patient may present with a complication of polycythemia vera. Approximately 33% of patients present with thrombosis or hemorrhage; 75% of these have arterial thrombosis, and 25% have venous thrombosis. In the previously mentioned study by Szuber et al, the incidence of venous thrombosis was found to be higher in patients with polycythemia vera aged 40 years or younger than in older patients with the disease. [11] Cerebrovascular accidents, myocardial infarction, deep venous thrombosis, and pulmonary embolism (in order of decreasing frequency) can result from thrombosis due to polycythemia vera.
Budd-Chiari syndrome (hepatic vein thrombosis) is less common in polycythemia vera but is more specific to it. A patient who presents with Budd-Chiari syndrome should alert the physician to consider polycythemia vera because it is the most common underlying disease. Approximately 2-10% of patients with polycythemia vera have Budd-Chiari syndrome. Many presenting patients do not have an elevated hematocrit at the time of presentation but have other polycythemia vera laboratory abnormalities; if they survive, they eventually develop a myeloproliferative phenotype.
One study of 41 patients with idiopathic Budd-Chiari syndrome found that 58% of these patients had the JAK2V617F mutation. [15] Another group reported that patients with Budd-Chiari syndrome and the JAK2V617F mutation can have an elevated serum erythropoietin (Epo) level. [16] Classically, the presence of an elevated Epo level was believed to make the diagnosis of polycythemia vera extremely unlikely.
Less than 5% of patients have erythromelalgia (ie, erythema and warmth of the distal extremities, especially of the hands and feet, with a painful burning sensation that can result in digital ischemia if prolonged). A role for platelet aggregation has been proposed; in fact, the syndrome responds frequently (but not always) within hours to low-dose aspirin therapy.
Less commonly, polycythemia vera presents with cardiovascular symptoms due to myocardial infarction and congestive heart failure, pulmonary hypertension from chronic thromboembolic disease, neurological symptoms due to spinal cord compression by extramedullary hematopoiesis, and elevated uric acid with subsequent gout due to increased cell turnover.
Unrecognized hepatic or splenic vein thrombosis can result in portal hypertension and varices. Other GI symptoms include peptic ulcer disease, which occurs 4-5 times more frequently than in the general population. Hemorrhagic presentations are usually mild, with gum bleeding and easy bruising; however, serious GI hemorrhage can occur. Forty percent of patients experience life-altering pruritus. Typically, the pruritus is worse after a warm shower or bath; this is known as aquagenic pruritus. It has been attributed to increased numbers of mast cells and elevated histamine levels.
Physical
Potential physical findings include plethora and ruddiness of the face, erythromelalgia of the distal extremities, bruising, and splenomegaly. Specific attention should be directed towards sternal tenderness, which may indicate transformation to acute myeloid leukemia. [2]
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Bone marrow film at 400X magnification demonstrating dominance of erythropoiesis. Courtesy of U. Woermann, MD, Division of Instructional Media, Institute for Medical Education, University of Bern, Switzerland.
