Table 2: ANN-ARBOR staging system.

Stage Definition
I Disease in single lymph node or lymph node region
II Disease in two or more lymph node regions on same side of diaphragm
III Disease in lymph node regions on both sides of the diaphragm
IV Disease is widespread, by hematogenic route, including multiple involvement at one or more extranodal sites
E Extranodal invasion by contiguity
X Large tumor (diameter > 10 cm mediastinal-thoracic ratio > 1/3)
B With symptoms (weight-loss > 10%, sweats, fever)