It has roughly the same function as TNM staging in solid tumors.
The stage depends on both the place where the malignant tissue is located (as located with biopsy, CT scanning, gallium scan and increasingly positron emission tomography) and on systemic symptoms due to the lymphoma ("B symptoms": night sweats, weight loss of >10% or fevers).
The principal stage is determined by location of the tumor:[citation needed] These letters can be appended to some stages:[citation needed] The nature of the staging is (occasionally) expressed with:[citation needed] The staging does not take into account the grade (biological behavior) of the tumor tissue.
The prognostic significance of bulky disease, and some other modifiers, were introduced with the "Cotswolds modification".
[1] The Ann Arbor classification is named after Ann Arbor, Michigan, where the Committee on Hodgkin's Disease Staging Classification met in 1971;[2] it consisted of experts from the United States, UK, Germany and France, and replaced the older Rye classification from a 1965 meeting.