Thyroid cancer staging is done with the TNM staging system.
TNM staging system
Tumour stage not including anaplastic carcinoma
| T stage
|
Size/criteria
|
Other requirements
|
Comment
|
| pT1a
|
1 cm or less
|
limited to thyroid
|
very common
|
| pT1b
|
>1 cm and <=2 cm
|
limited to thyroid
|
|
| pT2
|
>2 cm and <=4 cm
|
limited to thyroid
|
|
| pT3
|
>4 cm and limited to thyroid (pT3a) or extension into strap muscles (e.g sternothyroid m., sternothyroid, thyrohyoid, omohyoid) (pT3b)
|
|
| pT4a
|
any size
|
any of the following: subcutaneous tissue, trachea, esophagus, larynx, recurrent laryngeal nerve
|
|
| pT4b
|
any size
|
any of the following: mediastinal vessels, encasing carotid artery, prevertebral fascia
|
|
Lymph nodes
| N stage
|
Criteria
|
Comment
|
| pN0
|
negative for lymph node metastasis
|
|
| pN1a
|
metastasis to level VI or VII
|
level VI = pretracheal, paratracheal, prelaryngeal/Delphian, perithyroidal; VII = mediastinal lymph nodes
|
| pN1b
|
metastasis to level I, II, III, IV, V, or retropharyngeal
|
|
Note:
- Level VI = central neck dissection.
See also