Myeloproliferative neoplasms

A heterogeneous group of proliferative disorders of the precursors of red and white blood cells, and platelets in the bone marrow. It leads to abnormalities in the number, maturation, or functioning of these cells, although depending on the type, one line or another will be affected to a greater extent. A global annual incidence of 2.17 cases per 100,000 inhabitants and variable progression and prognosis has been estimated.

The following types of myeloproliferative neoplasms have been described: chronic myelogenous leukemia, polycythemia vera, primary myelofibrosis (or chronic idiopathic myelofibrosis), essential thrombocythemia, chronic neutrophilic leukemia, and chronic eosinophilic leukemia.

The exact cause is unknown, but it is likely that a series of factors are involved. Available studies have shown that there is usually a change in the genetic material of the bone marrow cells producing the growing precursors, acquired over time, as only very rare cases occur in families.

Additionally, several factors have been described that would contribute to the risk of these myeloproliferative neoplasms:

• Age: it can occur at any age but is frequently diagnosed from the age of 50.
• Very high doses of ionizing radiation, chemotherapy, or radiation therapy for a previous malignant tumor.
• Prolonged exposure to high levels of chemical compounds such as benzene (also present in tiny amounts in cigarette smoke) or toluene.
• Other myeloproliferative disorders: a small fraction of myelofibrosis cases result from a complication of essential thrombocythemia or polycythemia vera.

They often present no symptoms and are detected accidentally during a routine analysis. Once symptoms appear, there is great variability among individuals, and they progress gradually over time, including:

• Headaches, dizziness, fever.
• Blurred vision.
• Fatigue, weakness.
• Bruises, petechiae (red spots under the skin), frequent bleeding.
• Unexplained weight loss.
• Difficulty breathing.
• Itching or skin irritation.
• Night sweats.
• Increased blood pressure.

Additionally, in all of them, there is to a greater or lesser degree medullary fibrosis and splenomegaly and hyperuricemia as a consequence of proliferation. Generally, the chronic course tends to evolve towards global bone marrow failure or, more frequently, towards acute leukemia.

Currently, there are no guidelines related to the prevention of myeloproliferative neoplasms, as the exact triggers are unknown. However, as with other conditions, it is advisable to follow a healthy lifestyle based on a balanced diet, regular physical exercise, and to avoid harmful habits such as smoking or excessive consumption of alcohol and other substances of abuse.