How is acute lymphocytic leukemia found?

At this time there are no special tests that can find acute lymphocytic leukemia (ALL) early. The best way to find it early is to report any possible signs or symptoms of leukemia to the doctor right away.

Signs and symptoms of acute lymphocytic leukemia

Certain signs and symptoms could suggest that a person might have acute lymphocytic leukemia. But tests are needed to confirm this. And keep in mind that these symptoms are most often caused by something other than cancer.

General symptoms: General symptoms of ALL can include weight loss, night sweats, tiredness, fever, and loss of appetite. Of course, ALL is not the only thing that causes these symptoms. They are most often caused by something other than cancer.

Problems caused by low blood cell counts: Most symptoms of ALL are caused by a shortage of normal blood cells, which happens when the leukemia cells crowd out normal blood-making cells in the bone marrow. As a result, the person doesn't have enough normal red blood cells, white blood cells, and platelets. These shortages show up on blood tests, and they can also cause symptoms.

• Anemia is a shortage of red blood cells. It can cause a person to feel tired, weak, dizzy, cold, lightheaded, or short of breath.
• A shortage of normal white blood cells increases the risk of infections. Although people with leukemia may have very high white blood cell counts, the cells are often not normal and cannot protect against infection. Fevers and other signs of infection are common symptoms of ALL.
• A shortage of blood platelets can lead to easy bruising, bleeding, frequent or severe nosebleeds, and bleeding gums.

Swelling in the belly: Leukemia cells may collect in the liver and spleen, causing them to swell. This may be noticed as a fullness or swelling of the belly.

Swollen lymph nodes: ALL can spread to lymph nodes. If the nodes are close to the surface of the body, they may be noticed as lumps under the skin. Lymph nodes inside the chest or belly (abdomen) may also swell, but these can be found only by tests like CT or MRI scans.

Spread to other organs: Less often, ALL can spread outside of the bone marrow to other organs. If it spreads to the brain or spinal cord (central nervous system), it can cause symptoms like headaches, weakness, seizures, vomiting, trouble with balance, or blurred vision. ALL may also spread to the chest, where it can cause fluid build-up and trouble breathing.

Bone or joint pain: Some patients have bone pain or joint pain caused by the build-up of leukemia cells in bones or joints.

Spread to other organs: Less often, ALL may spread to other organs, where it may form tumors.

Symptoms from an enlarged thymus: One type of ALL (the T-cell subtype) often affects the thymus, which is a small organ in the middle of the chest behind the breastbone and in front of the windpipe. A swollen thymus can press on the windpipe, causing coughing or trouble breathing. A large vein, the superior vena cava (SVC) that carries blood from the head and arms back to the heart, also passes next to the thymus. If the thymus presses on the SVC, it can cause the head and arms to swell (this is called SVC syndrome). This can affect the brain and is life threatening. People with SVC syndrome need treatment right away.

Tests to find ALL

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 about your health (take a medical history), such as how long you have had symptoms and whether or not you have any risk factors.

The doctor will do a physical exam to look for any swollen lymph nodes, any bleeding or bruising, or signs of infection. Blood tests will likely be done. If these suggest leukemia, your doctor may refer you to a doctor who treats blood diseases (called a hematologist), who may do one or more of the tests described below.

Types of tests used to look for acute lymphocytic leukemia

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

Bone marrow samples: The bone marrow aspiration and biopsy are tests used to take samples of bone marrow. 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 ½ inch long) is removed with a slightly larger needle.

Both samples are usually taken at the same time from the back of the hip (pelvic) bone. The patient usually lies on his or her stomach and the skin over the area is cleaned. Before the samples are taken, the skin and the surface of the back of the hip bone are numbed with medicine. Then the doctor makes a small cut in order to put in a needle.

The aspiration is done first. During aspiration, the sucking out is often painful for a moment. Then the biopsy needle is moved through the bone with a twisting motion. Sometimes the pressure of the needle going into the bone is painful, but it only lasts a short time. After the biopsy is done, pressure will be put on the site to help prevent bleeding.

These tests are used to tell whether a person has leukemia. They may also be done during treatment to see how well the treatment is working.

Spinal fluid: A lumbar puncture (or spinal tap) is done to look for leukemia cells in the cerebrospinal fluid (CSF), which is the liquid around the brain and spinal cord. For this test, the patient is usually lying on their side. The doctor first numbs an area in the lower back over the spine. A small needle is then put through the skin between the bones of the spine. Then some of the liquid is taken out. The fluid is looked at to see if it has leukemia cells in it. A lumbar puncture can also be used to put drugs into the CSF to try to prevent or treat the spread of leukemia to the spinal cord and brain.

Lab tests for acute lymphocytic leukemia

One or more lab tests may be done on the samples to decide if a person has acute lymphocytic leukemia (ALL), to find out what subtype of ALL it is, and/or to help learn how advanced the disease is.

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 ALL have too many white blood cells, not enough red cells, and not enough platelets. 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. These findings may suggest a person has leukemia, but usually a sample of bone marrow cells must be looked at to be sure.

People already known to have leukemia will have these tests to see how well treatment is working. They will also have other tests to measure the amount of certain chemicals in the blood to help tell how well their kidneys and liver are working and to make sure the blood is clotting as it should.

Tests on bone marrow and other samples: A doctor with special training in blood diseases looks at any biopsy samples (bone marrow 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 look 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. Normally, blasts are never more than 5% of bone marrow cells. A person with ALL has at least 20% to 30% blasts in their bone marrow.

Special lab tests: Sometimes doctors can’t tell what type of leukemia someone has just by counting and looking at the cells. Other special tests that look at blood, bone marrow, and even DNA, help the doctor decide which type of leukemia a person has. You might hear some of the following terms used: cytochemistry, flow cytometry, cytogenetics, PCR, and FISH. These are complex medical and chemical tests. Your doctor can tell you which of these you might need. You can learn more about these tests in our document, Leukemia: Acute Lymphocytic.

Imaging tests

Imaging tests make pictures of the inside of the body. Because leukemia does not usually form tumors, imaging tests are not always as helpful as they are for other types of cancer. 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 of the chest may be taken to see if a person may have a lung infection. The x-ray can also show swollen lymph nodes in the chest.

CT (computed tomography) scans: This is a special kind of x-ray test in which a beam moves around the body, taking pictures from different angles. The pictures are combined by a computer to show a slice of the body. This test can help tell if any lymph nodes or organs in your body are swollen.

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 slides 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.

Before the scan you may get an injection of a contrast dye, or you may be asked to drink some contrast material. This helps doctors tell normal areas from abnormal ones. 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 allergies or a reaction to any contrast material used for x-rays.

Sometimes a test that combines the CT scan with a PET scan (PET/CT scan) is done. For a PET scan, glucose (a form of sugar) that has a radioactive atom is put into the blood. The amount of radioactivity used is very low. Cancer cells in the body absorb large amounts of the sugar. A special camera can then create a picture of areas of radioactivity in the body. The doctor can then compare areas of higher radioactivity on the PET scan with the more detailed appearance of that area on the CT.

MRI (magnetic resonance imaging): MRI scans are very helpful in looking at the brain and spinal cord. These scans use strong magnets and radio waves instead of x-rays to make detailed pictures of the body. MRI scans take longer than CT scans. You may be placed inside a tube, which can feel confining. Newer, more open MRI machines may sometimes be another option. The MRI machine makes loud buzzing and thumping noises that you may find disturbing. Some places give you headphones to block this noise out.

Ultrasound: Ultrasound is the use of sound waves to make images of the organs. It can help to show whether the kidneys, liver, or spleen are enlarged. It can also be used to look at lymph nodes. This is an easy test to have done. For most ultrasounds 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 use a slightly radioactive chemical that is put into the blood. The chemical collects in areas of cancer or infection. These areas, called "hot spots," can be picked up by a special camera. These tests are not often done in people with ALL, but they can be useful when a person has bone pain that might be caused by either infection or cancer in the bones.