Table 1. Primary Tumor (T)a
| aReprinted with permission from AJCC: Gallbladder. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 211-7. | |
| TX | Primary tumor cannot be assessed. |
| T0 | No evidence of primary tumor. |
| Tis | Carcinoma in situ. |
| T1 | Tumor invades lamina propria or muscular layer. |
| T1a | Tumor invades lamina propria. |
| T1b | Tumor invades muscular layer. |
| T2 | Tumor invades perimuscular connective tissue; no extension beyond serosa or into liver. |
| T3 | Tumor perforates the serosa (visceral peritoneum) and/or directly invades the liver and/or one other adjacent organ or structure, such as the stomach, duodenum, colon, pancreas, omentum, or extrahepatic bile ducts. |
| T4 | Tumor invades main portal vein or hepatic artery or invades at least two extrahepatic organs or structures. |
