Table 5.
American Joint Committee on Cancer TNM Classification (Thyroid Cancer)
| Description | |
|---|---|
| Primary tumor (T)a | |
| TX | Primary tumor cannot be assessed |
| T0 | No evidence of primary tumor |
| T1 | Tumor 2 cm or less in greatest dimension, limited to the thyroid |
| T1a | Tumor 1 cm or less, limited to the thyroid |
| T1b | Tumor more than 1 cm, but not more than 2 cm, in greatest dimension, limited to the thyroid |
| T2 | Tumor more than 2 cm, but not more than 4 cm, in greatest dimension, limited to the thyroid |
| T3 | Tumor more than 4 cm in greatest dimension limited to the thyroid, or any tumor with minimal extrathyroid extension (e.g., extension to sternothyroid muscle or perithyroid soft tissues) |
| T4a | Moderately advanced disease; tumor of any size extending beyond the thyroid capsule to invade subcutaneous soft tissues, larynx, trachea, esophagus, or recurrent laryngeal nerve |
| T4b | Very advanced disease; tumor invades prevertebral fascia or encases carotid artery or mediastinal vessels |
| Regional lymph nodes (N)b | |
| NX | Regional lymph nodes cannot be assessed |
| N0 | No regional lymph node metastasis |
| N1 | Regional lymph node metastasis |
| N1a | Metastasis to level VI (pretracheal, paratracheal, and prelaryngeal/Delphian lymph nodes) |
| N1b | Metastasis to unilateral, bilateral, or contralateral cervical (levels I, II, III, IV, or V) or retropharyngeal or superior mediastinal lymph nodes (level VII) |
| Distant metastases (M) | |
| M0 | No distant metastasis |
| M1 | Distant metastasis |
| Anatomic stage/prognostic groups | |
| Stage I | T1, N0, M0 |
| Stage II | T2, N0, M0 |
| T3, N0, M0 | |
| Stage III | T1, N1a, M0 |
| T2, N1a, M0 | |
| T3, N1a, M0 | |
| Stage IVA | T4a, N0, M0 |
| T4a, N1a,M0 | |
| T1, N1b, M0 | |
| T2, N1b, M0 | |
| T3, N1b, M0 | |
| T4a, N1b, M0 | |
| Stage IVB | T4b, any N, M0 |
| Stage IVC | Any T, any N, M1 |
Modified from the 7th Edition of the American Joint Committee on Cancer Staging Manual, with permission of Springer-Verlag New York, Inc., 175 Fifth Avenue, New York, NY 10010, USA.
a
All categories may be subdivided: (s) solitary tumor and (m) multifocal tumor (the largest determines the classification).
b
Regional lymph nodes are the central compartment and the lateral cervical and upper mediastinal lymph node compartments.