Because more than one lymph node can be involved, it is important to find out which ones are affected and where they are located in the body. This process is called staging. The following table contains an example of a classification system that describes how widespread the disease is. The Ann Arbor staging system is most commonly used for non-Hodgkin lymphoma in adults.
Stages Found in Lymphomas
|I||Stage I occurs when there is a single lymphoid area (such as the spleen), a pair of areas (tonsils), or a group of related areas (the tonsils and adenoids) involved. It also occurs when cancer is found only in one area of a single organ outside of the lymph system.|
|II||Stage II occurs when there are two or more lymphoid areas involved, but they are on the same side of the diaphragm (the muscle under the rib cage that controls breathing and separates the chest and abdomen). An example of this would be the tonsils and one underarm lymph node. It also occurs when the lymphoma extends from a single lymph node group into a nearby organ, or when it affects groups of lymph nodes on the same side of the diaphragm.|
|III||Stage III occurs when there is involvement on both sides of the diaphragm (above and below), such as a node in the neck and another in the abdomen. It also occurs if the cancer has spread into an area or organ next to the lymph nodes, into the spleen, or both.|
|IV||Stage IV has involvement throughout the body and, in particular, in major sites such as the bone marrow.|
Staging allows the health practitioner to determine what choices of therapy are available. For example, if a person has Stage I with only one node involved, then surgically removing that node may result in a cure. On the other hand, if the person is at Stage IV, then surgical removal is not generally possible.
The most commonly used staging tests performed in the clinical laboratory are the complete blood count (CBC), liver and kidney function studies, and bone marrow biopsy. Non-laboratory tests include CT scans, MRI evaluations, and X-ray procedures.