Acute lymphocytic leukemia (ALL) is a cancer of lymphocytes, cells that live in the spongy inner mass of bone called the marrow. ALL is also called acute lymphoid leukemia or acute lymphoblastic leukemia. ALL is most common in young children and adults over age 50.

The lymph nodes are small, bean-shaped organs of the immune system. They are found in clusters in the abdomen, pelvis, underarms, and neck. Lymph nodes are part of the lymph system, which is made up of thin tubes that branch to all parts of the body. The job of the lymph system is to filter impurities from the body. The lymph system carries lymph, a colorless fluid containing white blood cells.

In ALL, non-inherited genetic changes cause the body to produce too many marrow cells called lymphoblasts. In normal bone marrow, lymphoblasts make lymphocytes, a kind of white blood cell found in the blood and lymph. Lymphocytes mature to help the body defend itself from infection. In people with ALL, these cells never mature.

Because blood carries cancer cells throughout the body, the cancer will spread around the body and may invade other organs, including the brain, liver and spleen. Unlike solid tumors, spread of ALL to other parts of the body does not always mean the cancer is in an advanced stage, but leukemia that has spread may require special treatment.

ALL is one of four types of leukemia. Like acute myelogenous leukemia (AML), ALL appears and progresses quickly, but begins in a different type of cell. Chronic lymphocytic leukemia and chronic myelogenous leukemia both progress more slowly.

Leukemia is either acute or chronic. In acute leukemia, the abnormal blood cells are blasts that remain very immature and cannot carry out their normal functions. The number of blasts increases rapidly, and the disease becomes worse quickly. In chronic leukemia, some blast cells are present, but in general, these cells are more mature and can carry out some of their normal functions. Also, the number of blasts increases less rapidly than in acute leukemia. As a result, chronic leukemia worsens gradually.

Previous chemotherapy and exposure to radiation may affect the risk of developing ALL.

Possible risk factors for ALL include the following:

* Being male.
* Being white.
* Being older than 70 years of age.
* Past treatment with chemotherapy or radiation therapy.
* Exposure to atomic bomb radiation.
* Having a certain genetic disorder such as Down syndrome.


Possible signs of adult ALL include fever, feeling tired, and easy bruising or bleeding.

The early signs of ALL may be similar to the flu or other common diseases. A doctor should be consulted if any of the following problems occur:

* Weakness or feeling tired.
* Fever.
* Easy bruising or bleeding.
* Petechiae (flat, pinpoint spots under the skin caused by bleeding).
* Shortness of breath.
* Loss of appetite or weight loss.
* Pain in the bones or stomach.
* Pain or feeling of fullness below the ribs.
* Painless lumps in the neck, underarm, stomach, or groin.


These and other symptoms may be caused by adult acute lymphoblastic leukemia or by other conditions.

Tests that examine the blood and bone marrow are used to detect (find) and diagnose adult ALL.

The following tests and procedures may be used:

* Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
* Complete blood count: A procedure in which a sample of blood is drawn and checked for the following:
o The number of red blood cells, white blood cells, and platelets.
o The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
o The portion of the blood sample made up of red blood cells.
* Peripheral blood smear: A procedure in which a sample of blood is checked for the presence of blast cells, number and kinds of white blood cells, the number of platelets, and changes in the shape of blood cells.
* Bone marrow biopsy and aspiration: The removal of a small piece of bone and bone marrow by inserting a needle into the hipbone or breastbone. A pathologist views the samples under a microscope to look for abnormal cells.
* Cytogenetic analysis: A test in which the cells in a sample of blood or bone marrow are looked at under a microscope to find out if there are certain changes in the chromosomes in the lymphocytes. For example, sometimes in ALL, part of one chromosome is moved to another chromosome. This is called the Philadelphia chromosome.
* Immunophenotyping: A test in which the cells in a sample of blood or bone marrow are looked at under a microscope to find out if malignant (cancerous) lymphocytes began from the B lymphocytes or the T lymphocytes.


Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

* The age of the patient.
* Whether the cancer has spread to the brain or spinal cord.
* Whether the Philadelphia chromosome is present.
* Whether the cancer has been treated before or has recurred (come back).


As we well know, there are many kinds of cancer; unfortunately they all come about because of the out-of-control growth of abnormal cells.