CS Extension

Notes

**Note 1**: AJCC considers all anaplastic carcinomas to be T4. **Note 2**: AJCC considers "in situ carcinoma of thyroid gland" an impossible diagnosis. Any case so coded is mapped to TX for AJCC stage and in situ Summary Stage. **Note 3**: The assignment of T1 and T2 categories for carcinoma of the thyroid is based on tumor size. A physician's statement of the T category may be used to code both CS Tumor Size and/or CS Extension if this is the only information in the medical record regarding one or both of these fields. However the two fields are coded independently; for example, the record may document size but not extension. Use codes 405, 410, 415, 420, 490, 560, 810, and 815 as appropriate to code CS Extension based on a statement of T when no other extension information is available. **Note 4**: Use code 300 for localized tumor only if no information is available to assign codes 100, 200, 400, 405, 410, 415, 420, or 490. **Note 5**: Extension codes 405, 410, 415, 420, and 490 are not compatible with anaplastic carcinomas of the thyroid.
Code Description AJCC 7 T AJCC 6 T Summary Stage 1977 T Summary Stage 2000 T
000 In situ, intraepithelial, noninvasive Determine Correct Table for T Determine Correct Table for T IS IS
100 Single invasive tumor confined to thyroid Determine Correct Table for T Determine Correct Table for T L L
200 Multiple foci confined to thyroid Determine Correct Table for T Determine Correct Table for T L L
300 Localized, NOS Determine Correct Table for T Determine Correct Table for T L L
400 Into thyroid capsule, but not beyond Determine Correct Table for T Determine Correct Table for T L L
405 Stated as T1a with no other information on extension Determine Correct Table for T Determine Correct Table for T L L
410 Stated as T1b with no other information on extension Determine Correct Table for T Determine Correct Table for T L L
415 Stated as T1 [NOS] with no other information on extension Determine Correct Table for T Determine Correct Table for T L L
420 Stated as T2 with no other information on extension Determine Correct Table for T Determine Correct Table for T L L
450 Minimal extrathyroid extension including:
Strap muscle(s):
Omohyoid
Sternohyoid
Sternothyroid
Thyrohyoid
Determine Correct Table for T Determine Correct Table for T RE RE
480 Pericapsular soft tissue/connective tissue Determine Correct Table for T Determine Correct Table for T RE RE
490 Stated as T3 with no other information on extension Determine Correct Table for T Determine Correct Table for T L L
500 Parathyroid
Nerves:
Recurrent laryngeal
Vagus
Determine Correct Table for T Determine Correct Table for T RE RE
520 Cricoid cartilage
Esophagus
Larynx
Sternocleidomastoid muscle
Determine Correct Table for T Determine Correct Table for T RE RE
550 Trachea Determine Correct Table for T Determine Correct Table for T D D
560 Stated as T4a with no other information on extension Extension T4 SSF1 AJCC7 T4a Histology Grade Extension Summary Stage Histology Grade Extension Summary Stage
600 Thyroid cartilage
Tumor described as "FIXED to adjacent tissues"
Extension T4 SSF1 AJCC7 T4b RE RE
620 Blood vessel(s) (major):
Carotid artery (encased)
Jugular vein
Thyroid artery or vein
Extension T4 SSF1 AJCC7 T4b RE RE
650 (600 or 620) + 550

Any structures in code 600 or 620 plus trachea
Extension T4 SSF1 AJCC7 T4b D D
700 Bone
Skeletal muscle, other than strap or sternocleidomastoid muscle
Extension T4 SSF1 AJCC7 T4b D D
720 OBSOLETE DATA CONVERTED V0200
See code 550

Trachea
ERROR: ERROR: ERROR: ERROR:
730 700 + 550

Any structures in code 700 plus trachea
Extension T4 SSF1 AJCC7 T4b D D
800 Further contiguous extension including:
Mediastinal tissues
Prevertebral fascia
Extension T4 SSF1 AJCC7 T4b D D
810 Stated as T4b with no other information on extension Extension T4 SSF1 AJCC7 T4b D D
815 Stated as T4 [NOS] with no other information on extension Extension T4 SSF1 AJCC7 T4NOS RE RE
950 No evidence of primary tumor Determine Correct Table for T Determine Correct Table for T U U
999 Unknown; extension not stated
Primary tumor cannot be assessed
Not documented in patient record
Determine Correct Table for T Determine Correct Table for T U U
- For CS Extension codes 000, 100-550, 950, and 999 ONLY, the T category for AJCC 7 staging is assigned based on the value of CS Tumor Size and/or CS Extension and CS Site-Specific Factor 1 as shown in the Extension Size SSF 1 AJCC 7 Table for all histologies except 8020, 8021, 8030, 8031, and 8032, or any other histology with grade equal to 4. For these histologies or grade 4, the T category for AJCC 7 staging is assigned based on the value of CS Extension and CS Site-Specific Factor 1 as shown in the Histology Grade Extension SSF 1 AJCC 7 Table. - For CS Extension codes 560-700 and 730-815 ONLY, the T category for AJCC 7 staging is assigned based on the value of CS Extension and CS Site-Specific Factor 1 as shown in the Extension T4 SSF 1 AJCC 7 Table. - For CS Extension codes 000, 100-550, 950, and 999 ONLY, the T category for AJCC 6 staging is assigned based on the value of CS Tumor Size and/or CS Extension as shown in the Extension Size AJCC 6 Table for all histologies except 8020, 8021, 8030, 8031, and 8032, or any other histology with grade equal to 4. For these histologies or grade 4, the T category for AJCC 6 staging is assigned based on the value of CS Extension as shown in the Histology Grade Extension AJCC 6 Table. - For CS Extension code 560 ONLY, the value for SS1977 and SS2000 is assigned based on the value of histology and grade as shown in the Histology Grade Extension Summary Stage Table.