Table 1. Primary Tumor (T)a,b
| TX | Primary tumor cannot be assessed. |
| T0 | No evidence of primary tumor. |
| Tis | High-grade dysplasia.c |
| T1 | Tumor invades lamina propria, muscularis mucosae, or submucosa. |
| T1a | Tumor invades lamina propria or muscularis mucosae. |
| T1b | Tumor invades submucosa. |
| T2 | Tumor invades muscularis propria. |
| T3 | Tumor invades adventitia. |
| T4 | Tumor invades adjacent structures. |
| T4a | Resectable tumor invading pleura, pericardium, or diaphragm. |
| T4b | Unresectable tumor invading other adjacent structures, such as aorta, vertebral body, trachea, etc. |
| aReprinted with permission from AJCC: Esophageal and esophagogastric junction. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 103-15. |
| b(1) At least maximal dimension of the tumor must be recorded, and (2) multiple tumors require the T(m) suffix. |
| cHigh-grade dysplasia includes all noninvasive neoplastic epithelia that was formerly called carcinoma in situ, a diagnosis that is no longer used for columnar mucosae anywhere in the gastrointestinal tract. |
