My diagnostic approach in case of isolated
erythrocytosis is based on the visit and the interview of patients, and on checking the causes of secondary
erythrocytosis. If causes of secondary
erythrocytosis are not evident and serum
erythropoietin level is low-normal, I study JAK2 mutations. In the case of a patient with
erythrocytosis and other signs of myeloproliferation, such as
leukocytosis,
thrombocytosis or
splenomegaly, the diagnosis of
polycythemia vera (PV) is likely, and I test serum
erythropoietin and JAK2 mutations first. I stratify patients at diagnosis of PV according to age and history of
thrombosis. I start
hydroxyurea for patients who are at a high risk of
thrombosis (that is, with one or two risk factors), while I continue only phlebotomy in other cases. All PV patients, if not contraindicated, receive
aspirin. I follow up patients monthly until normalization of their blood cell counts or
splenomegaly, and afterwards every 2 months with visit, cell blood count and blood smear evaluation. After diagnosis, I perform bone marrow biopsy only in the case of clinical signs of disease evolution.