In oncology, polycythemia vera (PV) is an uncommon myeloproliferative neoplasm in which the bone marrow makes too many red blood cells.

[1] The majority of cases[2] are caused by mutations in the JAK2 gene, most commonly resulting in a single amino acid change in its protein product from valine to phenylalanine at position 617.

Common signs and symptoms include itching (pruritus), and severe burning pain in the hands or feet that is usually accompanied by a reddish or bluish coloration of the skin.

A classic symptom of polycythemia vera is pruritus or itching, particularly after exposure to warm water (such as when taking a bath),[5] which may be due to abnormal histamine release[6][7] or prostaglandin production.

[12][13] Splenomegaly may cause the spleen to be palpable in some patients, which has been reported by Lee et al. (2022) to be associated with both the V617F mutation and the development of myelofibrosis.

[16] The WHO criteria for polycythemia vera are specifically outlined in Table 4, and emphasis is given to accurate histological observations as proven predictors in the prognosis of the disease.

As summarized by Verstovek following the 2016 European Hematology Association Congress,[17] there are 3 major criteria for PV diagnosis: Patients usually have a very low level of erythropoietin, a growth factor that increases the production of red blood cells, which may be considered a minor diagnostic feature.

[21] Some patients may lose the normal allele in the diseased cells entirely together with the short arm of chromosome 9 (9p), likely due to mitotic recombination causing copy-neutral loss of heterozygosity.

Studies show the median survival rate of controlled Polycythemia Vera ranges from 10 to 20 years; however, most observations are of people diagnosed in their 60s.

[32] The tendency of some practitioners to avoid chemotherapy if possible, especially in young patients, is a result of research indicating possible increased risk of transformation to acute myelogenous leukemia (AML).