Idiopathic myeloproliferative neoplasm characterized by increased red cell mass that is rare in childhood. Manifestations are caused by occlusive vascular lesions.
Vaquez Disease; Osler-Vaquez Disease; Vaquez Polycythemia; Polycythemia Vera.
44 to 57 per 100,000 in general population; affects males more often than females.
Activating mutation in the tyrosine kinase JAK2.
Evocated accidentally on routine blood examination. Diagnosis is usually made by the clinical findings of erythrocytosis, leukocytosis, thrombocytosis, and splenomegaly. Also, the association of blood examination and several signs, such as headaches, weakness, dyspnea, dizziness, or tinnitus, might confirm the diagnosis. However, only two or three of these criteria may be present. Direct determination of red cell mass has also been suggested, but is of uncertain value because of the difficulties in standardization and because of expense. Occasionally reported in childhood, it occurs mostly in middle-age males. Diagnosis can be confirmed by the association of splenomegaly, arterial saturation more than 92%, and an increased red blood cell (RBC) mass (>36 mL/kg in men and 32 mL/kg in women). Treatment includes phlebotomy and myelosuppression.
Vaquez-Osler disease is a myeloproliferative disease. Hyperplasia involves all marrow elements and replaces marrow fat. There is increased production and turnover of red blood cells, neutrophils, and platelets. Insidious onset usually in the sixth decade of life. Erythrocytosis, neutrophilia, thrombocytosis, and splenomegaly are present. Thrombosis (10% with Budd-Chiari Syndrome; 50% of patients develop at least one thrombotic complication, which includes cardiovascular accident, myocardial infarction [MI], deep venous thrombosis, and pulmonary embolism). Bleeding and bruising, although usually minor. Pruritus, peptic ulcer disease, gastric varices, angina, MI, congestive heart failure, and dizziness. Reports of spinal cord compression from extramedullary hemopoiesis. Gout, secondary to increased urate turnover. Increased perioperative bleeding and thrombosis. Associated with lymphocytic lymphomas. Clinical features can also include headache, mental clouding, facial plethora pruritus, hepatomegaly, high blood pressure, and gout. More severe manifestations, caused by occlusive vascular lesions, can also be observed: transient ischemic attack, digital ischemia, stroke, bleeding (including gastrointestinal tract). Death occurs within 18 months without treatment and within 15 years with appropriate treatment, but there is a 20% incidence of transformation to myelofibrosis and approximately a 5% incidence of transformation to acute leukemia.
Precautions before anesthesia
Hematology consultation for recommendations regarding phlebotomy, cytoreductive therapy, low-dose aspirin, or anticoagulation. Check complete cell blood count and coagulation status. Postpone elective surgery in presence of myocardial angina and congestive heart failure. Evaluate cardiac function in cases of high blood pressure (clinical, chest radiographs, ECG, echocardiography). Determine toxicity secondary to chemotherapeutics. Evaluate vasoocclusive risk (full history, platelet count, hematocrit, leukocytes) and hepatic function (echocardiography, CT, laboratory investigations, including serum glutamic-oxaloacetic transaminase ...