Table 1.

Staging systems of gastric mucosa-associated lymphoid tissue lymphoma

Lugano staging system for gastrointestinal lymphoma	TNM staging system modified for gastric lymphoma	Ann Arbor staging system modified by Musshoff	Tumor involvement
I = Confined to GI tract (single primary or multiple, noncontiguous)	T1 N0 M0	IE1	Mucosa, submucosa
	T2 N0 M0	IE2	Muscularis propria Serosa
	T3 N0 M0
II = Extending into abdomen
II1 = Local nodal involvement	T1-3 N1 M0	IIE1	Perigastric lymph nodes
II2 = Distant nodal involvement	T1-3 N2 M0	IIE2	More distant regional lymph nodes
IIE = Penetration of serosa to involve adjacent organs or tissues	T4 N0 M0	IE	Invasion of adjacent structures
IV = Disseminated extra-nodal involvement or concomitant supradiaphragmatic nodal involvement	T1-4 N3 M0	IIIE	Lymph nodes on both sides of the diaphragm
	T1-4 N0-3 M1	IVE	Distant metastases (e.g., bone marrow or additional extranodal sites)

GI: Gastrointestinal; TNM: Tumor node metastasis.