Serum erythropoietin (EPO) is often used to differentiate primary polycythemia or polycythemia vera (PV) from secondary polycythemia. The current major criteria for diagnosis of PV are high hemoglobin (Hb) level, > 18.5 g/dL for males, > 16.5 g/dL for females and the presence of JAK2 gene mutation while panmyelosis of the bone marrow, and low EPO level are minor criteria. Herein, I reported a 6...