Primary polycythemia/ Polycythemia vera
- a.k.a polycythemia rubra vera; erythremia
- common in age 60 – 75
- overproduction of all three hematopoietic cell lines with predominant elevation in red cell counts
- mutation in the JAK2 protein which regulates marrow production
- red cells grow wildly despite a Low erythropoietin level
- high serum leukocyte alkaline phosphate
- Headache, blurred vision, and tinnitus
- pruritus, especially after hot bath (due to histamine release from increased numbers of basophils)
- HTN, facial plethora, fatigue, Splenomegaly
- Bleeding from engorged blood vessels
- Thrombosis from hyperviscosity
- elevated Hct >60%*
- low MCV and Low iron (because of excessive usage and production)
- however, Vit. B12 levels are elevated for unclear reason
- exclude hypoxia first; normal Oxygen level and *low erythropoietin level in PV
- initial 1st line – Phlebotomy and aspirin prevent thrombosis – target Hct 45%
- Hydroxyurea helps lower the cell count
- indicated in old age >70 years; has thrombosis; has a platelet count >1500; and has cardiovascular risk factors
- Allopurinol or rasburicase protects against uric acid rise
- Interferon alpha may be used in refractory cases
Kidney cancer is an important differential diagnosis of secondary polycythemia.
Renal Cell Carcinoma is a neoplastic condition that can initially appear with many different paraneoplastic manifestations.
The initial presentation may include hypertension, flank mass, gross or microscopic hematuria, hypercalcemia, fever, weight loss, and/or polycythemia.
Polycythemia may be the presenting sign in 3% of cases of kidney cancer.
Careful evaluation is important in patients presenting with polycythemia and hematuria.
Polycythemia is secondary to a hypersecretion of tumor cytokines, including renin.
The patient’s erythropoietin level is usually high.
Surgical removal of the cancer resolves the polycythemia.