ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors can use to find the cause of a medical problem. Use the menu to see other pages.

Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If the cancer has spread, it is called metastasis. Doctors may also do tests to learn which treatments could work best.

For most types of cancer, a biopsy is the only sure way for the doctor to know if an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

How childhood Hodgkin lymphoma is diagnosed

There are many tests used for diagnosing childhood Hodgkin lymphoma. Not all tests described here will be used for every person, and the timing and sequence of these tests may vary depending on your child's specific situation. Your child’s doctor may consider these factors when choosing a diagnostic test:

• The type of cancer suspected

• Your child’s signs and symptoms

• Your child's age and general health

• The results of earlier medical tests

The following tests may be performed to diagnose Hodgkin lymphoma:

• Physical examination/Blood tests. Children tend to have larger lymph nodes than adults. Usually, a child has enlarged lymph nodes for several weeks or months before a doctor suspects Hodgkin lymphoma, which is uncommon in this age group. The doctor first looks for signs of a more common infection that may cause the lymph nodes to swell and may prescribe antibiotics.

  If swelling in the lymph nodes does not go down after a course of antibiotics, the swelling may be caused by something other than an infection. In these instances, the doctor does a physical examination of all the lymph node areas, the liver, and the spleen, which may be enlarged in children or teens with Hodgkin lymphoma.
  
  Blood tests may also be done to check blood counts and evaluate how the liver and kidneys are working. There is no specific blood test for Hodgkin lymphoma, but changes in blood counts, such as unexplained anemia or a low number of red blood cells, are sometimes more common in people with Hodgkin lymphoma.

• Biopsy. If the lymph nodes do not feel normal when the doctor examines them and do not respond to antibiotics, the doctor will check tissue from the abnormal lymph node for cancer cells. The process of removing the tissue for examination is called a biopsy.

  Hodgkin lymphoma makes a distinctive kind of abnormal cell, called a Reed-Sternberg cell, which is easily identified under the microscope. The only way to diagnose Hodgkin lymphoma is to look at the tissue from an abnormal lymph node under the microscope. A pathologist is the specialist who analyzes the sample(s). A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease.

  To perform a standard biopsy for Hodgkin lymphoma, a surgeon cuts through the skin and removes an entire lymph node or a piece of a mass of lymph nodes. In children, a lymph node biopsy is usually performed with general anesthesia or conscious sedation, in which the child is awake but the pain and discomfort are lessened with medication.

  Sometimes, a doctor may first try to obtain tissue from the lymph node by doing a fine needle aspiration biopsy. In this test, a thin needle is used to remove small amounts of fluid and tissue from the lymph node. This type of biopsy may not provide enough tissue to diagnose the disease, so it is recommended only when a standard, surgical biopsy cannot be done.

If a biopsy confirms the diagnosis of Hodgkin lymphoma, several tests and scans can help the doctor learn more about the disease and, through a process called staging, show how far the disease has spread. The tests and scans can also show how well treatment is working. Tests may include:

• X-ray. An x-ray is a way to create a picture of the structures inside of the body using a small amount of radiation. For instance, a chest x-ray will show whether lymph nodes in the mediastinum are enlarged. A mediastinal tumor that takes up one-third or more of the chest cavity is considered "bulky." It may cause coughing or breathing problems by narrowing the airway.

• Computed tomography (CT) scan. A CT scan takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed, 3-dimensional or 3D image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to provide better detail on the image. The dye can be injected into a patient’s vein and/or given as a pill or liquid to swallow. The CT scan shows if lymph nodes in the chest or abdomen are enlarged, which may be a sign of cancer. Also, this test will show if other organs, such as the lungs, liver, or spleen, are involved.

• Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. MRI can be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein and/or given as a pill or liquid to swallow. This test may be used instead of or in addition to a CT scan at diagnosis or during follow-up care to check for lymphoma in the abdomen, bones, or lymph nodes in the chest.

• Positron emission tomography (PET) scan or PET-CT scan. A PET-CT scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. However, the amount of radiation in the substance is too low to be harmful. A scanner then detects this substance to produce images of the inside of the body. PET scans are often used to add to the information gathered from a CT scan and physical examination. PET scans are an important tool used to evaluate how well treatment is working for Hodgkin lymphoma. Before treatment, areas of active Hodgkin lymphoma appear bright on the scan in most people. During and after treatment, these bright areas usually go away as the cancer cells are being destroyed. This test can reassure families and doctors—without doing a biopsy—that scar tissue still present on a CT scan after treatment does not contain active cancer cells, and it will help to determine how much additional treatment is necessary.

• Bone marrow biopsy. Hodgkin lymphoma rarely spreads to the bone marrow in children with disease that is only in the lymphatic system. Bone marrow has both a solid and liquid part. In many cases, a PET scan (see above) can be used to find out if the lymphoma involves the bone marrow. The doctor may recommend a bone marrow biopsy if they believe that a PET scan will not be effective for your child. A bone marrow biopsy is the removal of a small amount of solid tissue using a needle, usually from bone in the pelvis, which is located in the lower back by the hip. Doctors generally give a type of medication called "anesthesia" beforehand to numb the area, or more commonly, conscious sedation is given while a needle is inserted. Anesthesia is medication that blocks the awareness of pain. Stronger types of anesthesia can also be used to lessen the pain. A pathologist will analyze the sample(s) obtained from the biopsy to determine if the lymphoma involves the bone marrow.

After diagnostic tests are done, your child’s doctor will review the results with you. If the diagnosis is Hodgkin lymphoma, these results also help the doctor describe the cancer. This is called staging.

The next section in this guide is Stages and Groups. It explains the system doctors use to describe the extent of the disease. Use the menu to choose a different section to read in this guide.