Ann Arbor staging is the staging system for lymphomas, both in Hodgkin's lymphoma (formerly designated Hodgkin's disease) and non-Hodgkin lymphoma (abbreviated NHL). It was initially developed for Hodgkin's, but has some use in NHL. 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).