The purpose of staging is to determining whether the lymphoma has spread.
CT scan or PET scan imaging and, depending on the lymphoma type, bone marrow biopsies are used to stage lymphomas.
The Ann Arbor staging system is routinely used for staging of both HL and NHL. In this staging system, I represents a localized disease contained within a lymph node station, II represents the presence of lymphoma in two or more lymph node stations on the same side of the diaphragm, III represents spread of the lymphoma to both sides of the diaphragm, and IV indicates lymphoma outside a lymph node, such as bone marrow, blood or other organs.
It is important to keep in mind that lymphoma is “cancer of the immune system”. The immune system is represented everywhere in the body and often lymphomas are found to be spread (stage IV). However, contrary to other cancers, stage IV high grade lymphomas remain curable.