Walsh & Hoyt: Diagnosis

Criteria for the diagnosis of polycythemia vera were developed by the Polycythemia Vera Study Group and include an increased red blood cell mass, normal arterial oxygen saturation, and splenomegaly. Patients without splenomegaly may also be diagnosed with polycythemia vera if, in addition to increased red blood cell mass and normal arterial oxygen saturation, there is thrombocytosis, leukocytosis, an increased granulocyte alkaline phosphatase, or an increased serum concentration of vitamin B12. Strict adherence to these criteria may, however, exclude patients in the early stages of the disease.