Table 4. Anatomic Stage/Prognostic Groupsa,b
| Stage | T | N | M |
| Papillary or follicular (differentiated) |
| YOUNGER THAN 45 YEARS |
| I | Any T | Any N | M0 |
| II | Any T | Any N | M1 |
| 45 YEARS AND OLDER |
| I | T1 | N0 | M0 |
| II | T2 | N0 | M0 |
| III | T3 | N0 | M0 |
| T1 | N1a | M0 |
| T2 | N1a | M0 |
| T3 | N1a | M0 |
| IVA | T4a | N0 | M0 |
| T4a | N1a | M0 |
| T1 | N1b | M0 |
| T2 | N1b | M0 |
| T3 | N1b | M0 |
| T4a | N1b | M0 |
| IVB | T4b | Any N | M0 |
| Stage IVC | Any T | Any N | M1 |
| Medullary carcinoma (all age groups) |
| I | T1 | N0 | M0 |
| II | T2 | N0 | M0 |
| T3 | N0 | M0 |
| III | T1 | N1a | M0 |
| T1 | N1a | M0 |
| T2 | N1a | M0 |
| T3 | N1a | M0 |
| IVA | T4a | N0 | M0 |
| T4a | N1a | M0 |
| T1 | N1b | M0 |
| T2 | N1b | M0 |
| T3 | N1b | M0 |
| T4a | N1b | M0 |
| Stage IVB | T4b | Any N |
| IVB | T4b | Any N | M0 |
| IVC | Any T | Any N | M1 |
| Anaplastic carcinoma c |
| IVA | T4a | Any N | M0 |
| IVB | T4b | Any N | M0 |
| IVC | Any T | Any N | M1 |
| aReprinted with permission from AJCC: Thyroid. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 87-96. |
| bSeparate stage groupings are recommended for papillary or follicular (differentiated), medullary, and anaplastic (undifferentiated) carcinoma. |
| cAll anaplastic carcinomas are considered Stage IV. |
