Gastrointestinal Stromal Tumors: A Review of Case Reports, Diagnosis, Treatment, and Future Directions

Table 3

The new TNM risk stratification system [59].

TNM classification for gastric GIST including primary, solitary omental GISTs
Stage	T	N	M	Mitotic rate per 50 hpf
Stage IA	T1,T2	N0	M0	<5
Stage IB	T3	N0	M0	<5
Stage II	T1, T2	N0	M0	>5
	T4	N0	M0	<5
Stage IIIA	T3	N0	M0	>5
Stage IIIB	T4	N0	M0	>5
Stage IV	Any T	N1/Any N	M0/M1	Any rate
TNM classification for small intestinal GIST including esophagus, colon, rectum, mesentery, and other less common sites
Stage	T	N	M	Mitotic rate per 50 hpf
Stage IA	T1,T2	N0	M0	<5
Stage II	T3	N0	M0	<5
Stage IIIA	T1	N0	M0	>5
	T4	N0	M0	<5
Stage IIIB	T2, T3, T4	N0	M0	>5
Stage IV	Any T	N1/any N	M0/M1	Any rate
T-primary tumor
TX	cannot be assessed
T0	no evidence of primary tumor
T1	Tumor ≤2 cm
T2	Tumor >2 cm to 5 cm
T3	Tumor >5 cm to 10 cm
T4	Tumor >10 cm
N-regional lymph node
NX	cannot be assessed
N0	No lymph node involvement
N1	Lymph node involvement
M-distant metastasis
M0	No distant metastasis
M1	Distant metastasis