CS Extension
Notes
**Note 1**: 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 2**: AJCC does not include a T1 or T2 category for mucosal melanoma of head and neck sites. **Note 3**: Use codes 205 and 310 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 4**: Use code 300 for localized tumor only if no information is available to assign code 105, 205, or 320. **Note 5**: Use code 320, 638, 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 one of the following subsites: Laryngopharynx Postcricoid area Posterior pharyngeal wall Pyriform sinus |
ERROR: | NA | L | L |
| 105 | Tumor confined to mucosa of one of the following subsites: Laryngopharynx Postcricoid area Posterior pharyngeal wall Pyriform sinus |
T3 | NA | L | L |
| 150 | OBSOLETE DATA CONVERTED V0200 See code 420 Code 100 with tumor fixation |
ERROR: | ERROR: | ERROR: | ERROR: |
| 200 | OBSOLETE DATA RETAINED V0200 Tumor invades more than one subsite of hypopharynx (listed in code 100) WITHOUT fixation |
ERROR: | NA | L | L |
| 205 | Tumor involves mucosa of more than one subsite of hypopharynx (listed in code 105) WITHOUT fixation |
T3 | NA | L | L |
| 300 | Localized, NOS | T3 | NA | L | L |
| 310 | Involvement of mucosa only: Larynx Nasopharynx Oropharynx |
T3 | NA | RE | RE |
| 320 | Stated as T3 with no other information on extension | T3 | NA | L | L |
| 400 | OBSOLETE DATA RETAINED V0200 Oropharynx |
ERROR: | NA | RE | RE |
| 410 | Involvement of deep soft tissue or musculature of any structure in code 105 or 205 Soft tissue, NOS |
T4a | NA | L | L |
| 415 | 410 + 310 Involvement of deep soft tissue or musculature of any structure in code 105 or 205 plus mucosal involvement of any structure in code 310 |
T4a | NA | RE | RE |
| 420 | Involvement of any structure in code 105 or 205 WITH tumor fixation |
T4a | NA | RE | RE |
| 430 | Involvement of deep soft tissue or musculature of any structure in code 310 | T4a | NA | RE | RE |
| 450 | OBSOLETE DATA RETAINED V0200 Code 200, 300, or 400 with tumor fixation |
ERROR: | NA | RE | RE |
| 500 | OBSOLETE DATA RETAINED V0200 Larynx |
ERROR: | NA | RE | RE |
| 510 | OBSOLETE DATA CONVERTED V0104 See code 450 Any of codes 100-400 WITH fixation of tumor or fixation, NOS |
ERROR: | ERROR: | ERROR: | ERROR: |
| 550 | Fixation of hemilarynx or larynx | T4a | NA | RE | RE |
| 600 | Central compartment soft tissues of neck including: Prelaryngeal strap muscles Subcutaneous fat |
T4a | NA | D | D |
| 610 | Esophagus | T4a | NA | RE | RE |
| 620 | Thyroid gland | T4a | NA | D | RE |
| 630 | Cricoid cartilage Thyroid cartilage Cartilage, NOS |
T4a | NA | D | RE |
| 635 | Hyoid bone Bone excluding base of skull Bone, NOS Overlying skin |
T4a | NA | D | D |
| 638 | Stated as T4a with no other information on extension | T4a | NA | L | L |
| 640 | Prevertebral fascia/muscle(s) | T4b | NA | RE | RE |
| 645 | 640 + 635 Prevertebral fascia/muscles plus any structure in code 635 |
T4b | NA | D | D |
| 650 | Carotid artery (encased) | T4b | NA | D | RE |
| 655 | 650 + 635 Carotid artery plus any structure in code 635 |
T4b | NA | D | D |
| 660 | OBSOLETE DATA CONVERTED V0200 See code 635 Hyoid bone |
ERROR: | ERROR: | ERROR: | ERROR: |
| 700 | Mediastinal structures | T4b | NA | D | D |
| 800 | OBSOLETE DATA RETAINED V0200 Further contiguous extension |
ERROR: | 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 |