Erythrocytosis

Erythrocytosis is an expansion of red cell mass, which can be clonal and non-clonal in nature. A detailed history including smoking exposure, symptoms suggestive of sleep apnea, and the presence of some types of malignancies (i.e., renal carcinoma) could facilitate recognition of non-clonal erythrocytosis. Accurate diagnosis of JAK2 617F or JAK 2 exon 12 clonal erythrocytosis is important for prevention of thrombotic complications. In this chapter, we summarize clinical manifestations, etiologies, and management of clonal and non-clonal erythrocytosis.