Doctors are able to diagnose lymphomas based on how they look under a microscope, the chromosome features of the lymphoma cells, and the presence of certain chemicals on the surface of the cells. Sometimes, non-Hodgkin lymphomas may be difficult to diagnose. Consult with your doctor to ensure that accurate testing is completed to receive the right treatment for you.

In order to diagnose NHL, your doctor will order several tests, including a physical exam, blood tests, biopsies, and imaging tests to confirm the exact type and stage of your disease. This will help the doctor determine the best treatment options for you. 

Lymph Node Biopsy - The doctor will remove a piece of the lymph node and examine it under a microscope. This is the only way to know for sure if the swelling is caused by cancer. 

Bone Marrow Biopsy- The doctor will insert a needle into your hipbone to check to see if lymphoma cells have travelled and are present in your bone marrow. 

If a biopsy confirms an NHL diagnosis, then your doctor may recommend additional tests to find out how far the disease has spread. These other tests include chest x-ray, CT scan, MRI, PET scan, and blood tests.


After confirming a NHL diagnosis, the doctor needs to know the stage, or extent, of the disease to plan the best treatment. Staging is a careful attempt to find out whether the cancer has spread, and if so, to what parts of the body.

The Ann Arbor Staging System is the system most commonly used by health care providers to describe the extent of non-Hodgkin lymphoma in adults. Stages are classified as Roman numerals I-IV (1-4). The higher the number, the more advanced the disease. Lymphomas that affect organs outside the lymph system (an extranodal organ) have an E added to the staging classification. Lymphomas affecting the spleen have an S added to the staging classification.

Stage I: The disease is found in only one lymph node or in a lymphoid organ such as the thymus gland (I). A lymphoma can be classified as Stage IE (extranodal) when it is found in one area of a single organ not involved in the lymph system (i.e. lung, liver, bone, etc.).

Stage II: The disease is found in two or more lymph node areas on the same side of the muscle beneath the lungs that separates the chest and abdomen (diaphragm) (IIE) or, the cancer has spread locally to a nearby organ next to the lymph nodes (IIE). 

Stage III: The disease is found in lymph nodes on both sides of the diaphragm or the NHL is present in lymph nodes above and below the diaphragm (III), and has also spread to nearby organs (IIIE), to the spleen (IIIS) or to both (IIIES). 

Stage IV: The disease has spread widely through one or more organs outside of the lymph system, such as liver, bone marrow, or lung, NHL is found in organs in two distant parts of the body and not in nearby lymph nodes, or NHL is diagnosed in the liver, bone marrow, lungs or cerebrospinal fluid (the liquid that surrounds the brain and spinal cord).

In addition, letters can be assigned to the stages. These are additional ways to categorize the disease.

- Letter "A" - Added if the symptoms known as “B” symptoms (listed below) caused by NHL are not present.

- Letter "B" - Added if these symptoms are present: A loss of more than 10 percent of body weight over six months (without dieting or over-exercising), a fever of 100.4°F (38 degrees Celsius) or greater without any known cause, and/or drenching night sweats.

- Letter "E" - Added to the stage and indicates that NHL has affected an organ outside of the lymph system but is present next to an affected lymph node.

- Letter "S" - Added to the stage, indicates that NHL is affecting the spleen.

- Letter "X" - Added to the stage to indicate that the diameter of tumors are at least 4 inches across, which may require more intense treatment. The addition of the letter “X” indicates that the tumor is “bulky”.

NHL is unique and different from HL in that doctors will use also the International Prognostic Index (IPI) score. The index depends on 5-factors, and is used for aggressive NHL lymphomas. The 5-factors include person’s age, stage of lymphoma, external involvement of organs present, how healthy he/she is and how well he/she can perform “normal activities of daily living”, and the LDH level in the person’s blood. The total number of points helps predict the risk of disease relapse. 

Updated 2/24/15