Leukemia is cancer of the white blood cells. Leukemic cells look different than normal white blood cells and do not function properly. Types of Leukemia There are four main types of leukemia: Acute myelogenous leukemia Chronic myelogenous leukemia Acute lymphocytic leukemia Chronic lymphocytic leukemia These types can be further divided into subtypes. When classifying the type of leukemia, the first steps are to determine if the cancer is: Lymphocytic or myelogenous leukemia; and Acute or chronic leukemia Cancer can occur in either the lymphoid (lymph node tissue) or myeloid (bone marrow) white blood cells. Lymphocytic leukemia: Cancer develops in the lymphocytes (lymphoid cells) Myelogenous leukemia: Cancer develops in the granulocytes or monocytes (myeloid cells) Leukemia is also either acute or chronic. Acute leukemia: The new or immature cancer cells, called blasts, remain very immature and cannot perform their functions. The blasts increase in number rapidly, and the disease progresses quickly. Chronic leukemia: There are some blast cells present, but they are more mature and are able to perform some of their functions. The cells grow more slowly, and the number increases less quickly, so the disease progresses gradually. Chronic leukemia may affect the skin, central nervous system, digestive tract, kidneys, and testicles. Diagnostic Procedures When diagnosing leukemia, a doctor performs a complete medical history, a physical examination, blood tests, and X-rays. Other diagnostic procedures that may be used include the following: Bone marrow aspiration and/or biopsy—a procedure that involves taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (called a core biopsy), usually from the hip bones, to be examined for the number, size, and maturity of blood cells and/or abnormal cells Complete blood count (CBC)—a measurement of size, number, and maturity of different blood cells in a specific volume of blood Computed tomography scan (also called a CT or CAT scan)—a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images (often called slices) of the body Magnetic resonance imaging (MRI)—a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body Ultrasound (also called sonography)—a diagnostic imaging technique that uses high-frequency sound waves and a computer to view internal organs as they function and to assess blood flow through various vessels Lymph node biopsy—a procedure performed to remove tissue or cells from the body for examination under a microscope Spinal tap/lumbar puncture—a procedure in which a special needle is placed into the lower back, into the spinal canal (the area around the spinal cord), to remove cerebral spinal fluid to determine if leukemia involves the central nervous system and to exclude the possibility of an infection or other problems Treatment Many factors contribute to a comprehensive leukemia treatment plan. Treatment for acute and chronic leukemias may include chemotherapy or targeted therapy medications, radiation therapy, bone marrow transplantation, biological therapy, blood transfusion, and medications.