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.
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.|
|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). An example of this would be the tonsils and one underarm lymph node.|
|III||Stage III occurs when there is involvement on both sides of the diaphragm, such as a node in the neck and another in the abdomen.|
|IV||Stage IV has involvement throughout the body and, in particular, in major sites such as the bone marrow.|
There is another staging system that uses location and prognostic factors such as age, symptoms, and certain laboratory tests in the development of a three-part system. Stage I involves one or two sites with none of the poor prognostic signs. Stage II has more than two sites involved and some poor prognostic signs. Stage III has widespread disease and significant signs of poor prognosis.
Staging allows the physician 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 CBC, liver and kidney function studies, and bone marrow biopsy. Non-laboratory tests include CAT scans, MRI evaluations, and x-ray procedures.