To diagnose Hodgkin’s lymphoma, a physician first will take the patient’s medical history and perform a complete physical examination. Because infections are the most common cause of enlarged lymph nodes, the physician will examine the area surrounding the swollen lymph nodes for an infection. If the physician suspects Hodgkin’s lymphoma, a biopsy of the area may be ordered.

Biopsies are the only way to definitively diagnose and classify Hodgkin’s lymphoma. The procedure involves removing a sample of lymph node tissue for examination under a microscope by a pathologist.  Excisional and incisional biopsies are the two procedures used to diagnose Hodgkin’s lymphoma. In these procedures, the physician cuts through the skin to remove an entire lymph node (excisional biopsy), or a small section of a large tumor (incisional biopsy). When the lymph node is located near the skin surface, the procedure is relatively simple, and can be done with local anesthesia. When the lymph node is inside the chest or abdomen, general anesthesia is required.

A fine needle aspiration (FNA) biopsy is another type of biopsy that may be ordered. In this procedure, a thin needle and a syringe are used to remove a small amount of fluid and tissue. Although this procedure cannot be used to diagnose Hodgkin’s lymphoma, it may be ordered when a physicians suspects lymph node swelling to be the result of infection or the spread of cancer from another body part. After Hodgkin’s lymphoma has been treated, an FNA may be ordered to check the body for signs that the disease is metastasizing (spreading) or recurring (coming back).   

After the tissue has been removed, it is examined for abnormalities. The size and shape of the cells are examined to determine if any of them are Reed-Sternberg cells. In some cases, biopsy results are inconclusive and additional biopsies may be needed. Special stains are sometimes ordered to examine the sample for the presence of CD 15 and CD 30 molecules, molecules usually found in Hodgkin’s lymphoma.

After a diagnosis has been confirmed, the disease will be staged. Staging is the process of determining how far the cancer has spread and the patient's outlook for recovery (prognosis). Results from the physical exam, biopsies, imaging tests and other tests are used to determine the stage of the disease. It is necessary to plan the most effective course of treatment.

Imaging tests used during the staging of Hodgkin’s lymphoma include:

• Chest x-ray. This test uses low doses of radiation to produce images of the chest. With Hodgkin’s lymphoma, enlarged lymph nodes may be detected in the chest.
  
  
• CAT scan (computed axial tomography). Also known as a CT scan, this test allows for multiple x-rays to be taken from different angles around the patient. The cross-sectional images of the patient’s body are analyzed by a computer. Frequently after the first set of images is taken, the patient receives an intravenous (I.V.) injection of a contrast material (dye) to better outline body parts and a second set of images is taken. CAT scans give a physician an enhanced look at the lymph nodes and organs (such as the liver and spleen). 

• Magnetic resonance imaging (MRI). A powerful magnetic field creates images of structures and organs within the body allowing a computer to produce very clear cross-sectional or three-dimensional images. Although this test is rarely used with Hodgkin’s lymphoma, it may be ordered to determine if the disease has spread to the spinal cord or brain. As with CAT scans, a contrast material may be injected in the patient to improve the quality of the images.
  
  
• Gallium scan. In this procedure, a patient receives an injection of gallium-67, a slightly radioactive substance that is often absorbed by areas of the body where Hodgkin’s lymphoma is present. A couple of hours after the injection, the patient is placed under a scanner that detects where the gallium has accumulated in the body and the image is recorded on film. These tests are useful for locating the disease in bones and organs.
  
  
• Positron emission tomography (PET) scan. In this procedure, the patient receives an injection of glucose (sugar) containing a small amount of radioactive material. The radioactive glucose is absorbed by the cancer cells in the body. A camera then scans the patient and detects where the radioactive glucose was absorbed. Areas of cancer appear as “hot spots” on the image. This test may be used to detect if and where cancer has spread in the body.
  
  
• Lymphangiogram. An x-ray examines the lymph nodes in the pelvis and abdomen. Blue dye is injected into the skin between the patient’s toes. The dye is picked up by lymph vessels causing them to become blue and allowing the physician to easily recognize them. This test is not used as often now for diagnosing and staging the disease.

Additional tests that may be ordered include:

• Blood tests. Although Hodgkin’s lymphoma cells do not appear in blood, a complete blood count (CBC) may be ordered to reveal signs of the disease including anemia and increased white blood cells. When Hodgkin’s lymphoma is in the liver, blood tests of liver function can have abnormal results. Sedimentation rate and blood chemistry studies may also be ordered.
  
  
• Bone marrow biopsy and aspiration. Usually completed together during the same procedure, a bone marrow biopsy and a bone marrow aspiration may be ordered to detect if the Hodgkin’s lymphoma is in the bone marrow. Although generally used for staging the disease, a bone marrow biopsy may be ordered on a rare occasion to diagnose Hodgkin’s lymphoma.
  
  
• Immunophenotyping. A sample of white blood cells is taken to determine the specific cell type and characteristics. The test may be used to determine if the malignant cells developed from B lymphocytes (B-cells) or T lymphocytes (T-cells).