Lymphoma is a cancer that develops in the lymphatic system, according to the University of Maryland Medical Center. The lymphatic system encompasses the organs and tissues that produce, store and carry white blood cells and includes the spleen, lymph nodes and bone marrow. Non-Hodgkins is the most common kind of lymphoma, and Hodgkins lymphoma is second. The "European Journal of Nuclear Medicine and Molecular Imaging" states that the American Joint Commission on Cancer, or AJCC, has adopted the Ann Arbor staging system to classify lymphoma.
Stage I
The American Cancer Society explains that the Ann Arbor staging system, adopted by the AJCC, uses Roman numerals I through IV to describe each stage of lymphoma. A physician will diagnose a lymphoma as stage I if it is present in a lymph node or nodes in only one region, or is found only in one area of a single organ outside of the lymph system.
Stage II
Stage II lymphoma in the Ann Arbor staging system involves lymphoma in two or more groups of lymph nodes on the same side of the diaphragm, the muscle that separates the abdomen and the chest. The involved nodes in stage II are either above or below the diaphragm. A physician will also diagnose lymphoma as stage II if it has spread from a single group of lymph nodes into a nearby organ or into other groups of lymph nodes on the same side of the diaphragm.
Stage III
Stage III lymphoma as described by the Ann Arbor staging system is present if the lymphoma is found in lymph node areas on both sides of the diaphragm, or if it has spread into an organ or area next to the lymph nodes, or into the spleen.
Stage IV
The final stage of lymphoma in the Ann Arbor staging system and adopted by the AJCC is stage IV. Stage IV includes either lymphoma that has spread outside of the lymph system into an organ not close to the involved node, or lymphoma that has spread to the bone marrow, brain, spinal cord or the lining of the lungs.
Alphabetical Descriptions
Alphabet symbols added to the stage number further define the extent of the lymphoma, according to the Mayo Clinic. The letter A indicates that a patient has no significant symptoms from the cancer. The letter B indicates that significant symptoms such as severe night sweats, fever and weight loss are present. The letter E stands for extranodal, meaning that the cancer has spread beyond the lymph nodes. The letter S signifies that the cancer has spread to the spleen.
