Polycythemia Vera

Bone marrow disorder

Science Photo Library - WLADIMIR BULGAR/Brand X Pictures/Getty Images

Polycythemia vera (PV) is a slowly progressive cancer of the bone marrow, in which too many red blood cells are produced. The symptoms of PV are largely related to the “thickness” of the blood caused by the excess red cells, in particular, blood clots and (paradoxically) easy bleeding. With good medical management, patients with PV can lead nearly normal lives.

PV occurs in about 1 in 100,000 individuals, most often those aged 50-70 years, but it may occur at any age.

This rare bone marrow disorder affects both men and women of all ethnic backgrounds.

Symptoms

The symptoms of polycythemia vera come on slowly. Because there are too many red blood cells, there is a higher volume of blood in the body than normal and therefore, it is thicker than usual and has difficulty circulating in small blood vessels. Symptoms may include:

  • poor oxygen circulation causing headache, dizziness, vertigo, ringing in the ears (tinnitus), vision changes, chest pain
  • abnormal bleeding causing nosebleeds, gums bleeding, bruising, digestive system bleeding
  • enlarged spleen (splenomegaly) and/or liver (hepatomegaly)
  • abnormal blood clots in veins in the body (thrombosis)
  • development of Budd-Chiari syndrome (obstruction of the main vein of the liver)
  • itching (pruritis), especially after a hot bath
  • ruddy (reddened) complexion which may be seen in the face, palms, nailbeds, mucous membranes in the mouth, and conjunctiva of the eye

    While PV is a type of bone marrow cancer, with good medical care most patients can expect to live their normal life span. However, patients with PV have an increased risk of developing more dangerous kinds of bone marrow cancer over time, such as acute leukemia.

    Diagnosis

    When polycythemia vera is suspected, perhaps from a high blood hematocrit or other symptoms, direct measurement of the red blood cell mass in the blood shows an increase.

    This combined with an enlarged spleen or increased white blood cell and platelet counts (which are also common in PV) will help confirm the diagnosis. There are additional tests which can be done to confirm the diagnosis and exclude other disorders which may cause similar symptoms.

    Treatment

    Polycythemia vera has for many years been treated by removing some blood from the body (phlebotomy). This procedure can reduce the increased number of red blood cells down to a normal level. Usually about one-half to one pint (250-500 ml) of blood is removed. When an individual is first diagnosed, phlebotomy may be done frequently.

    Once the individual's hematocrit value is normal, phlebotomy is typically performed on a maintenance basis, or may be combined with, or replaced by, myelosuppressive drugs such as hydroxyurea or interferon. If the platelet count is high, a platelet-reducing agent called anagrelide (Agrylin) may be used.

    An individual with polycythemia vera will be cared for by a hematologist (blood specialist) who has experience managing the treatment and complications of the disorder.

    Currently, there is no consensus in the medical community as to what the optimum treatment for PV is, so treatment is tailored to the needs of the individual. PV is a chronic condition which requires long-term treatment.

    Sources:

    Besa, E.C. (2006). Polycythemia vera. eMedicine, accessed at http://www.emedicine.com/med/topic1864.htm

    National Organization for Rare Disorders. Polycythemia Vera

    Edited by Richard N. Fogoros, MD

    Continue Reading