Table 1.
Ann Arbor staging system
| Stage | Defining status |
|---|---|
| Stage I | Restricted to single lymph node region (I) or a single extranodal site (I-E). |
| Stage II | Two or more areas of nodal involvement on the same side of the diaphragm (II) or one or more lymph node regions with an extranodal site (II-E). |
| Stage III | Lymphatic involvement on both sides of the diaphragm (III), possibly with an extranodal site (III-E), the spleen* (III-S), or both (III-SE). |
| Stage IV | Liver, marrow, or other extensive extranodal disease. |
| Substage | |
| Substage E | Localized, extranodal disease. |
| Substage A | Absence of systemic signs. |
| Substage B | Presence of unexplained weight loss (10% in 6 months), and/or unexplained fever, and/or night sweat. |
*The spleen is considered nodal