If Acute Lymphocytic Leukemia Is Suspected

Most of the symptoms seen in leukemia can also be caused by other problems like infections. For this reason, your doctor will focus on finding out if you really have leukemia.

Medical History and Physical Exam

The doctor will want to ask you questions (get a medical history), such as how long you have had symptoms and whether or not you have any risk factors.

The doctor will likely do a physical exam to look for any enlarged lymph nodes, any bleeding or bruising, or signs of infection. If there seems to be a problem with blood cell counts, blood tests will be done. If these suggest leukemia, your doctor may refer you to a cancer doctor, who may run one or more of the tests described below.

Types of Samples Used to Test for Acute Lymphocytic Leukemia

Blood samples: Blood samples for tests are generally taken from a vein in the arm.

Bone marrow samples: In bone marrow aspiration, a thin needle is used to draw up a small amount of liquid bone marrow. During a bone marrow biopsy, a small cylinder of bone and marrow (about ?inch long) is removed with a slightly larger needle.

Both samples are usually taken at the same time from the back of the hipbone. The patient usually lies on his or her side and the area is cleaned with a special soap. Before the sample is taken, the doctor injects medicine near the back of the hipbone to numb it. Then the doctor makes a small cut in order to insert a needle. The needle is moved through the bone with a twisting motion. Sometimes the needle going into the bone is painful, but it only lasts a short time. During aspiration, the sucking out is often painful for a moment.

These tests are used to tell whether leukemia is present and also, if you are having treatment, how well the treatment is working.

Spinal tap (lumbar puncture): For this test, a small needle is placed into the spinal cavity in the lower back to draw out some of the liquid around the brain and spinal cord (cerebrospinal fluid or CSF). The fluid is examined for leukemia cells. A lumbar puncture is also sometimes to put drugs into the fluid to keep leukemia from spreading into the brain or spinal cord, or to treat it if it has already spread there.

Lab Tests for ALL

Doctors use a number of very precise lab tests to diagnose and classify leukemia.

Blood cell counts and other blood tests: Changes in the numbers of different blood cell types and how the cells look under a microscope can suggest leukemia. Most people with acute lymphocytic leukemia (ALL) have too many white blood cells, not enough red cells, and not enough platelets. Also, many of the white cells will be blasts, a type of immature cell not normally found in the bloodstream. These cells don't work the way they should.

People already known to have leukemia will have tests done to measure the amount of certain chemicals in the blood. These tests do not tell whether they have leukemia but can help tell how well their kidneys and liver are working.

A doctor with special training in blood diseases looks at all of the biopsy samples (bone marrow, lymph node tissue, blood, and cerebrospinal fluid) under a microscope. The doctor looks at the size and shape of the cells as well as other features to classify the cells into specific types. An important goal of this process is to see whether the cells appear mature or not. The most immature cells are called blasts. The number of blasts in the bone marrow is important in telling whether a person has leukemia. Having at least 20% to 30% of blasts in the marrow is generally the benchmark for a diagnosis of ALL.

Other special tests which look at blood, bone marrow, and even DNA, help the doctor decide which type of leukemia a person has. These are complex medical and chemical tests. Your doctor can tell you which of these you might need.

Imaging Tests

Imaging tests are ways of producing pictures of the inside of the body. Because leukemia does not usually form tumors, imaging tests are not always helpful. For people with ALL, these tests are done more often to look for infections or other problems rather than for the leukemia itself.

X-rays: X-rays may be taken to see if there is a lung infection. The x-ray can also show enlarged lymph nodes in the chest.

CT (computed tomography) scans: These are special kinds of x-rays in which a beam moves around the body, taking pictures from different angles. The pictures are combined by a computer into an image of a slice of the body. CT scans are helpful in looking at internal organs. They can show pockets of infection, enlarged organs, and any large collection of leukemia cells.

CT scans take longer than regular x-rays. You need to lie still on a table while they are being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that completely surrounds the table. You might feel a bit confined while the pictures are being taken.

Often after the first set of pictures is taken, you will have an injection of a contrast dye, or you may be asked to drink some contrast material, to better outline blood vessels and organs. A second set of pictures is then taken.

The injection can cause you to feel flushed or warm, in the face or elsewhere. Some people get hives (itchy bumps). A few may have more serious allergic reactions like trouble breathing, feeling dizzy, or passing out. Be sure to tell the doctor before the scan if you have ever had a reaction to any contrast material used for x-rays.

MRI (magnetic resonance imaging): MRI scans use powerful magnets and radio waves to produce detailed pictures of the body. MRI scans are helpful in looking at the brain and spinal cord. MRI scans take longer than CT scans. Also, you may be placed inside a tube, which can feel confining. Newer, more open MRI machines can sometimes be found for some people if help with this is needed. The MRI machine makes loud buzzing noises that you may find disturbing. Some places provide headphones to block this out.

Ultrasound: Ultrasound is the use of sound waves to produce images of internal organs. It can help to show whether the kidneys, liver, or spleen are enlarged. This is an easy test to have done. You simply lie on a table and a kind of wand is moved over the part of your body being examined.

Gallium scan and bone scan: These tests involve injecting a slightly radioactive chemical into the blood. The chemical collects in areas of cancer or infection called "hot spots," where it can be seen by a special camera. These tests can be useful when a person has bone pain that might be caused by either infection or cancer involving bones.