CS Extension
Notes
**Note 1**: Connective tissues large enough to be given a specific name are considered adjacent structures. For example, prevertebral fascia and jugular vein have names. **Note 2**: AJCC does not include a Tis or TX category for melanoma of mucosa of head and neck sites. CS Extension codes of 000 and 999 are mapped to NA and AJCC stage group is derived as NA. **Note 3**: AJCC does not include a T1 or T2 category for mucosal melanoma of head and neck sites. **Note 4**: Use codes 405 and 430 for extension involving the mucosa only of adjacent sites. Use higher codes for extension involving the deeper tissues of the primary or adjacent sites. **Note 5**: Use code 300 for localized tumor only if no information is available to assign code 105, 470, or 530. **Note 6**: Use code 470, 725, 810, or 815 if the physician's assignment of T category is the only information available about the extent of the tumor.| Code | Description | AJCC 7 T | AJCC 6 T | Summary Stage 1977 T | Summary Stage 2000 T |
|---|---|---|---|---|---|
| 000 | In situ, intraepithelial, noninvasive | NA | NA | IS | IS |
| 100 | OBSOLETE DATA RETAINED V0200 Invasive tumor confined to site of origin |
ERROR: | NA | L | L |
| 105 | Tumor confined to mucosa of site of origin | T3 | NA | L | L |
| 300 | Localized, NOS | T3 | NA | L | L |
| 400 | OBSOLETE DATA RETAINED V0200 More than one region of pharynx involved (oropharynx, nasopharynx, hypopharynx) |
ERROR: | NA | RE | RE |
| 405 | Mucosa only of more than one region of pharynx involved: Oropharynx Nasopharynx Hypopharynx |
T3 | NA | RE | RE |
| 430 | Mucosa only of pharynx and oral cavity involved | T3 | NA | RE | RE |
| 470 | Stated as T3 with no other information on extension | T3 | NA | L | L |
| 500 | OBSOLETE DATA RETAINED V0200 Pharynx and oral cavity involved |
ERROR: | NA | RE | RE |
| 530 | Involvement of deep soft tissue or musculature of any structure in code 105 | T4a | NA | L | L |
| 535 | 530 + (400 or 500) Involvement of deep soft tissue or musculature of any structure in code 105 with mucosal involvement of any structure in code 405 or 430 |
T4a | NA | RE | RE |
| 540 | Involvement of deep soft tissue or musculature of any structure in code 405 or 430 | T4a | NA | RE | RE |
| 550 | Any of codes 105-430 WITH fixation | T4a | NA | RE | RE |
| 600 | Extension to adjacent structures (See Note 1) |
T4a | NA | RE | RE |
| 725 | Stated as T4a with no other information on extension | T4a | NA | L | L |
| 800 | Contiguous extension: Carotid artery (encased) Mediastinal structures Prevertebral space |
T4b | NA | D | D |
| 801 | Further contiguous extension including: Base of skull Brain Dura Lower cranial nerves (IX, X, XI, XII) Masticator space |
T4b | NA | D | D |
| 810 | Stated as T4b with no other information on extension | T4b | NA | D | D |
| 815 | Stated as T4 [NOS ] with no other information on extension | T4NOS | NA | L | L |
| 950 | OBSOLETE DATA RETAINED V0200 No evidence of primary tumor |
ERROR: | NA | U | U |
| 999 | Unknown; extension not stated Primary tumor cannot be assessed Not documented in patient record |
NA | NA | U | U |