Diagnosis

Doctors use many tests to diagnose cancer and determine if it has metastasized (spread) Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:

• Age and medical condition
  
  
• The type of cancer suspected
  
  
• Severity of symptoms
  
  
• Previous test results

The following tests may be used to diagnose Hodgkin lymphoma:

Physical examination. Children tend to have larger lymph nodes than adults. Usually, a child will have enlarged lymph nodes for several weeks or months before a doctor suspects Hodgkin lymphoma, which is uncommon in children. The doctor will first look for signs of more common infection that may cause the lymph nodes to swell and may prescribe antibiotics.

If swelling in the lymph nodes doesn’t go down after a course of antibiotics, the swelling may be caused by something other than an infection. The doctor will do a physical examination of all the lymph node areas, liver, and spleen, which may be enlarged in children 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 disease, but nonspecific changes in blood counts (such as unexplained anemia or low red blood cell counts) are sometimes more common in children with Hodgkin lymphoma.

Biopsy. If the lymph nodes don’t feel normal when the doctor examines them and don’t respond to antibiotics, the doctor will check tissue from the abnormal lymph node for cancer cells. Hodgkin lymphoma produces a distinctive kind of abnormal cell, called a Reed-Sternberg cell that is easily identified under the microscope. The only way to make the diagnosis of Hodgkin lymphoma is to look at the tissue from an abnormal lymph node under the microscope. The process of removing the tissue is called a biopsy.

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, lymph node biopsies are usually performed with general anesthesia or conscious sedation.

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 attached to a syringe is used to remove small amounts of fluid and tissue from the lymph node. This approach may not provide sufficient tissue to diagnose the disease, so it is recommended only when a standard, surgical biopsy is determined to be too difficult or dangerous.

After a biopsy confirms the diagnosis of Hodgkin lymphoma, several tests and scans can help the doctor learn more about the disease, show how far the disease has spread (a process called staging), and indicate how well treatment is working:

X-ray. An x-ray is a picture of the inside of the body. A chest x-ray will show whether lymph nodes in the mediastinum (chest cavity) are enlarged. Mediastinal masses that take up one-third or more of the chest cavity are considered "bulky." They may cause coughing or breathing problems because of narrowing of the airway.

Computed tomography (CT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a vein to provide better detail. 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 the organs, such as the lungs, liver, or spleen, are involved.

Positron emission tomography (PET) scans or gallium scans. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body and absorbed by organs or tissues being studied. This substance gives off energy that is detected by a scanner, which produces the images. PET scans are often used to complement information gathered from CT scan and physical examination. These tests are used to evaluate how well treatment is working. Before treatment, areas of active Hodgkin lymphoma appear black or "hot" on the scan in most people. During and after treatment, these "hot" areas usually go away as the cancer cells are dying. 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. If PET scans are not available, a different type of nuclear medicine test called a gallium scan may be performed instead.

Bone marrow biopsy. Hodgkin lymphoma rarely spreads to the bone marrow in children with localized Hodgkin lymphoma confined to the lymphatic system. Nonetheless, a bone marrow biopsy is recommended for most children, particularly when the presence of marrow disease would significantly affect the amount of treatment needed. Those with signs of more widespread disease involving lymph glands above and below the diaphragm, and those with other signs of Hodgkin lymphoma that has spread outside of the lymph node system to the lungs, liver, or bones, are more likely to have disease present in the bone marrow.

For this test, the child’s skin is numbed with a local anesthetic and a needle is inserted into the bone in the hip until it reaches the spongy part of the bone at the center, the bone marrow. A small amount of marrow is removed and examined under a microscope.

Bone scan. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark. This test shows whether Hodgkin lymphoma has spread to the bones. Bone metastases are not common in children with Hodgkin lymphoma, so this test is usually performed only in children who appear to have more advanced or widespread disease at the time of diagnosis. These include children with bone pain or other signs of spread of Hodgkin lymphoma outside of the lymphatic system.

To learn more about what to expect during common diagnostic tests, read Cancer.Net: Tests and Procedures.

To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: Newly Diagnosed.