| Stage | Classification |
| I | involvement of single lymph node region (I) or a single extralymphatic organ or site (IE) |
| II | involvement of two or more lymph node regions on the same side of the diaphragm (II) or on one or more lymph node regions plus an extralymphatic site (IIE) |
| III | involvement of lymph node regions on both sides of the diaphragm (III) (spleen is included here) subdivided into: III(1): involvement of spleen and/or splenic hilar, coeliac and portal nodes III(2): with para-aortic, iliac or mesenteric nodes |
| IV | involvement of one or more extralymphatic organs (lung, liver, bone, bone marrow) with or without lymph node involvement |
| Additional qualifiers | A: asymptomatic B: fever, night sweats, weight loss >10% body weight X: bulky disease (defined as lymph node mass > 10 cm in diameter or, if involving mediastinum, a mass greater than 1/3 of intrathoracic diameter at level of T5) E: involvement of a single extranodal site, contiguous with a known nodal site |