Marrow is the soft, fatty tissue inside the bones. The number of white blood cells in the bone marrow may become 20 to 40 times higher than normal. The cause of this form of cancer is unknown. CML develops mainly in people who are middle-aged.
Symptoms vary greatly.
Some people have none at all. The disease may be discovered during a routine blood test or during a routine physical exam when the doctor discovers an enlarged spleen. The disease can have a chronic phase and an accelerated phase. In about one person in four the chronic phase will develop into an accelerated phase, which is more serious. Symptoms of the accelerated phase may include include fever, bone pain, and bleeding.