Polycythemia vera is a clonal stem cell disorder characterized by increased total blood volume, elevated blood viscosity, and splenomegaly. It is more common in the elderly.

bubble_chart Diagnosis

I. Medical History and Symptoms

(1) Medical history inquiry: Pay attention to the onset (acute or gradual), history of thrombosis or bleeding, and whether accompanied by neurological symptoms. Check for a long-term high-altitude residence history. Inquire about any history of cardiopulmonary diseases and tumor diseases.

(2) Clinical symptoms: Dizziness, headache, tinnitus, lack of strength, forgetfulness, cutaneous pruritus, and limb numbness. There may also be diplopia, blurred vision, profuse sweating, foot pain, and weight loss. If thrombosis occurs, corresponding symptoms may appear.

II. Physical Examination Findings

Facial, hand, foot, and conjunctival congestion or grade I cyanosis, presenting a drunken appearance; 30% of patients have elevated blood pressure and hepatomegaly; over 75% have splenomegaly; occasional bone tenderness may occur. Petechiae or ecchymoses may be visible on the skin and mucous membranes.

III. Auxiliary Examinations

Blood tests: Hemoglobin ≥180 g/L (male), ≥170 g/L (female); red blood cell count ≥6.5×10^12/L (male), ≥6.0×10^12/L (female). White blood cell count >12.0×10⁹/L (without fever or infection). Platelet count >400×10⁹/L.

Bone marrow examination: Hyperplasia is markedly active, with proliferation of granulocytic, erythroid, and megakaryocytic series, especially prominent in the erythroid series.

Increased red cell mass: 51Cr-labeled red cell method: male >39 ml/kg, female >27 ml/kg.

Increased neutrophil alkaline phosphatase score >100 (without fever or infection).

Arterial blood oxygen saturation is normal (≥92%). Serum vitamin B12 is elevated (>666 pmol/L).

IV. Differential Diagnosis

It should be differentiated from high-altitude polycythemia, severe cardiopulmonary diseases, abnormal hemoglobinopathies; certain tumors (such as pheochromocytoma, liver cancer, kidney cancer, etc.), cysts, and secondary polycythemia caused by vascular abnormalities.

bubble_chart Treatment Measures

1. Venesection: Initially performed every 2-3 days, with 300-500 ml per session. After the hematocrit drops to 45%, perform venesection 3-4 times annually as needed to maintain hematocrit below 45%.

2. Chemotherapy: Hydroxyurea 0.5-1.5 g/day, orally; if hydroxyurea is unavailable, busulfan or chlorambucil 4-6 mg/day, orally. Reduce dosage or discontinue when hematocrit falls to 50%. Fortune plumyew twig and leaf ester alkaloid 1-2 mg/day, intravenous drip, administered for 10 days as one course.

3. Radioisotope 32P: 3-5 mCi, intravenous injection; or 2-4 mCi, orally, once weekly for two doses. Repeat after 4 months with adjusted dosage as appropriate. Suitable for elderly patients over 65 years old.

4. Interferon: 3 MU/day, intramuscular injection. After hematocrit drops below 45%, reduce frequency to 2-3 times per week for maintenance therapy, with a course lasting >6 months.

Symptomatic treatment:

① Secondary gouty arthritis: Administer allopurinol and indomethacin.

② Cutaneous pruritus: Cyproheptadine 4 mg, 3 times/day, orally; or astemizole 10 mg, 2 times/day, orally; or cimetidine 300 mg, 3 times/day, orally.