Hematologic cancers, (cancers of the blood, bone marrow, and lymph nodes) include leukemia, lymphoma, and myeloma. Every year, more than 100,000 cases of blood, bone marrow, and lymph node cancers are diagnosed in the United States, and more than 50,000 people die from these cancers. Among children and teens less than 20 years old, leukemia is the most common cancer and the leading cause of cancer death.
Leukemia is a cancer of the bone marrow and blood. The two main types of leukemia are lymphocytic leukemia, which involves an increase of white blood cells called lymphocytes; and myelogenous leukemia, which involves an increase in white blood cells called granulocytes. Leukemia can be acute or chronic. Acute forms of leukemia progress rapidly, while chronic forms of leukemia progress slowly.