The term leukemia is used to describe a group of neoplastic diseases primarily involving the bone marrow that are characterized by an abnormal proliferation of white blood cells (leukocytes). In acute lymphocytic leukemia and other acute varieties of the cancer, the onset of the disease is sudden and it progresses rapidly, whereas chronic leukemias develop gradually and slowly worsen over time.

As suggested by its name, a lymphocytic leukemia is one that affects lymphocytes, which in a healthy individual comprise about 20 to 30 percent of the total white blood cell count. Normally, lymphocytes and other mature white blood cells form from stem cells in the bone marrow. The source cells of lymphocytes, however, which are known as lymphoblasts, multiply uncontrollably in the bone marrow of patients with acute lymphocytic leukemia, interfering with the production of normal blood cells.

Acute lymphocytic leukemia does not appear to be an inherited condition. Instead, environmental factors, such as prenatal or childhood exposure to radiation, electromagnetic fields, or certain toxins, are generally believed to influence the likelihood that someone will develop the disease. Recently, benzene has been of particular concern for its potential link to some cases of acute lymphocytic leukemia, especially since the publishing of a preliminary study in 2004 that suggests that living near a gas station or auto repair shop, where benzene emissions in the air are at elevated levels, may quadruple the risk that a child will develop leukemia.

Without treatment, acute lymphocytic leukemia usually results in death only months after onset of the disease. Modern medical practices, including chemotherapy, radiation therapy, and bone marrow transplants, can greatly extend the lives of patients. Approximately 50 percent of individuals that receive treatment for the disease today achieve a complete cure, which is defined as being free of malignant cells for more than five years. Many others experience a full remission, but later suffer from a recurrence of the disease.

Lymphocytic Leukemia at 20x Magnification - Acute lymphocytic leukemia is the most common cancer that occurs in kids. Around 4,000 Americans are annually diagnosed with the disease, the majority of which are less than ten years old.

Lymphocytic Leukemia at 40x Magnification - Generally, the younger the patient is at the time the leukemia is diagnosed, the more likely they are to respond favorably to treatment.