Table 1. Modified Ann-Arbor criteria for Primary Nodal Lymphomas.

	Stage	Nodal Involvement	Extranodal involvement (E)
Limited	I	One node or a group of adjacent nodes	Only single extranodal lesions
	II	Two or more nodal groups on the same side of the diaphragm	Stage I or II by nodal extent with limited contiguous extranodal involvement
II bulky*		II as above with “bulky” disease	Not applicable
Advanced	III	Nodes on both sides of the diaphragm; nodes above the diaphragm with spleen involvement
	IV	Additional noncontiguous extralymphatic involvement

Note: extent of the disease is determined by PET/CT for FDG-avid lymphomas and CT for nonavid histologies

Tonsils, Waldeyer's ring, and spleen are considered nodal tissue

(E) Extranodal inolvement refers to extralymphtaic tissue, excluding liver and bone marrow

^*II bulky may be treated as limited or advanced desease based on histology and a number of prognostic factors