| T Grading |
T grading scale |
For papillary, follicular, hypofractionated, Hürthle cell, and undifferentiated thyroid carcinomas
undifferentiated cancers |
| TX |
Primary tumor cannot be evaluated |
| T0 |
No evidence of tumor |
| T1 |
Tumor confined to the thyroid with a maximum diameter of ≤2cm |
| T1a |
Tumor ≤1cm in maximum diameter |
| T1b |
Tumor maximum diameter >1cm, ≤2cm |
| T2 |
Tumor maximal diameter >2cm, ≤4cm |
| T3 |
Tumor >4cm and confined to the thyroid, or largely invading the extra-thyroidal band |
T3a
| Tumor >4cm and confined to the thyroid gland |
| T3b |
Large invasion of the extrathyroidal band muscles, regardless of tumor size (band muscles include: sternocleidomastoid, sternocleidomastoid, thyroglossus, scapulocleidomastoid) |
| T4 |
Largely invasive outside the extra-thyroidal band muscles |
T4a
| invasion of the larynx, trachea, esophagus, laryngeal denervation and subcutaneous soft tissues |
T4b
| invading the prevertebral fascia, or encapsulating the carotid artery and mediastinal vessels |
For medullary thyroid carcinoma
| TX |
Primary tumor cannot be evaluated |
| T0 |
No evidence of tumor |
| T1 |
Tumor confined to the thyroid with a maximum diameter of ≤2cm |
| T1a |
Tumor maximum diameter ≤1cm |
| T1b |
Tumor maximum diameter >1cm, ≤2cm |
| T2 |
Tumor maximal diameter >2cm, ≤4cm |
| T3 |
Tumor >4cm and confined to the thyroid gland, or largely invading the outer thyroid band
muscle |
T3a
| Tumor >4 cm and confined to the thyroid gland |
| T3b |
Large invasion of the extra-thyroidal band, regardless of tumor size |
T4
| locally advanced |
| T4a |
Moderately progressive, tumor of any size, invading peripheral cervical organs and soft tissues outside the thyroid
Tumors of any size invading peripheral organs and soft tissues of the neck outside the thyroid, such as the larynx, trachea, esophagus, laryngeal denervation, and subcutaneous soft tissues |
T4b
Severe progression, tumor of any size, invading the prevertebral fascia, or encapsulating the cervical arteries, mediastinal vessels
artery, mediastinal vessels |
N grade
| N grading criteria (for all thyroid cancers) |
NX
| Regional lymph node metastasis cannot be assessed |
| N0 |
No evidence of lymph node metastasis |
| N1 |
Regional lymph node metastasis |
| N1a |
Metastases to regions VI and VII (including paratracheal, pre-tracheal, anterior laryngeal/Delphian
or upper mediastinum) lymph nodes, either unilaterally or bilaterally |
| N1b |
Unilateral, bilateral, or contralateral lymph node metastases in the lateral cervical region (including regions I, II
III, IV, or V) or retropharyngeal lymph node metastases |
| M grade |
M grading criteria (for all thyroid cancers) |
M0
| No distant metastases |
| M1 |
with distant metastases |