Epidemiology
This disease is rare, with fewer than 1 in 10,000 people being diagnosed with HCL during their lives. Men are four to five times more likely to develop hairy cell leukemia than women. In the United States, the annual incidence is approximately 3 cases per 1,000,000 men each year, and 0.6 cases per 1,000,000 women each year.
Most patients are white males over the age of 50, although it has been diagnosed in at least one teenager. It is less common in people of African and Asian descent compared to people of European descent.
It does not appear to be hereditary, although occasional familial cases that suggest a predisposition have been reported, usually showing a common Human Leukocyte Antigen (HLA) type.
Read more about this topic: Hairy Cell Leukemia