Males and females with hematocrit values above 60% and 56%, respectively can be assumed the have absolute erythrocytosis and do not need red blood cell mass measurements.
Diagnosis of absolute erythrocytosis is made when the measured red cell mass is more than 25% above the mean predicted value for an individual’s body surface area.
primary erythrocytosis is caused by an intrinsic defect in the pathway that produces red cells in the bone marrow:JAK mutated polycythemia vera is the classic example.
Secondary erythrocytosis is due to erythropoietin driven red cell production in the erythroid compartment of the bone marrow.
Erythrocytosis can be congenial or acquired.
The condition is often asymptomatic, and an incidental finding, but a plethoric appearance may be present.
Some patients have vague symptoms: fatigue, headache, diffuse pruritus, blurred vision, slow mentation, and possible hyperviscosity.
Bone marrow aspirate and biopsy should be done in all patients with absolute erythrocytosis.
Marrow karyotype studies should be done on all bone marrow samples obtained to evaluate erythrocytosis.
Abdominal ultrasound indicated in all patients.