Types of leukemia
There are four main types of leukemia:
Another type of leukemia, hairy cell leukemia, is a rare subtype of chronic lymphocytic leukemia (CLL). It is caused by an increased number of lymphocytes and progresses very slowly. It is called “hairy” because of the appearance of the leukemia cells under a microscope.
The primary differences between the four main types of leukemia have to do with their rates of progression and where the cancer develops. "Chronic" leukemia cells do not mature all the way, so they are not as capable of defending against infections as normal lymphocytes. "Acute" leukemia cells begin to replicate before any immune functions have developed.