Table 1.

T N M classification of carcinoma of the ampulla of Vater

T (Primary tumour)
Tx	Primary tumour cannot be assessed
T1	Tumour limited to the ampulla of Vater or aphincter of Oddi
T2	Tumour invades duodenal wall
T3	Tumor invades 2 cm or less into pancreas
T4	Tumor invades more than 2 cm into pancreas and/or into other adjacent organs
N (Regional lymph nodes)
Nx	Regional lymph nodes cannot be assessed
NO	No regional lymph nodes metastasis
N1	Regional lymph nodes metastasis
M (Distant metastasis)
Mx	Distant metastasis not assessable
M0	No distant metastasis
M1	Distant metastasis: Hepatic metastasis, peritoneal dissemination, lymph nodes metastasis along the splenic vein or at the splenic hilum