The evaluation of clinical staging of thyroid tumors is based on visual examination and palpation of thyroid and regional lymph nodes. It is necessary to evaluate vocal cord movement under indirect laryngoscope. Various imaging methods can provide more useful information, including radionuclide thyroid scanning, ultrasound imaging, computer-aided tomography (CT) and magnetic resonance imaging (MRI) scanning. When tomography is used, MRI is recommended to avoid the pollution of iodine contrast agent to the whole body during CT examination. Iodine contrast agent will delay the use of radioactivity 13 1I after operation. The diagnosis of thyroid cancer must be confirmed by needle aspiration biopsy or surgical biopsy. Further information about clinical staging can be obtained from biopsy of lymph nodes or other local or distant sites that may metastasize. All information available before the first treatment should be used. Pathological staging Pathological staging requires the application of all the information obtained from clinical staging and histological examination of surgical specimens. Incomplete resection of the macroscopic residual tumor must also include the surgeon's evaluation. TNM defines primary tumor (T) Note: All classifications can be subdivided into: a. Solitary tumor; B. Multifocal tumors (the largest of which determines the stage). TX primary tumor cannot be evaluated. T 1 There is no evidence of primary tumor. The maximum diameter of the tumor is ≤2cm, which is confined to the thyroid gland. The largest diameter of T2 tumor is more than 2 cm, but less than 4 cm, and it is confined to the thyroid gland. The largest diameter of T3 tumor is more than 4 cm, and it is confined to thyroid or any tumor with minimal external invasion (such as sternal thyroid muscle or soft tissue around thyroid). T4a tumor, regardless of its size, T4b tumor exceeds the thyroid capsule and invades the subcutaneous soft tissue, larynx, trachea, esophagus or recurrent laryngeal nerve. All undifferentiated cancers that invade anterior vertebral fascia or surround carotid or mediastinal vessels belong to T4 tumor. T4a is limited to undifferentiated thyroid cancer-the undifferentiated cancer invaded by T4b outside the thyroid gland can be removed by surgery-regional lymph nodes cannot be removed by surgery (n) regional lymph nodes are middle cervical lymph nodes, lateral cervical lymph nodes and upper mediastinal lymph nodes NX regional lymph nodes cannot be evaluated. N0 regional lymph node metastasis N 1 regional lymph node metastasis N 1a VI group metastasis (pre-tracheal, paratracheal and pre-laryngeal/Delphi lymph nodes) N/Kloc-. B Metastasis to unilateral, bilateral or contralateral cervical or upper mediastinal lymph nodes (M) MX distant metastasis can not be evaluated M0 without distant metastasis M 1 papillary carcinoma with distant metastasis or follicular carcinoma under 45 years old? Any T in stage I, any NM0 II, any T, any NM 1 papillary carcinoma or follicular carcinoma? Over 45 years old? Phase I T1N0m0II T2N0m0III T3N0m0t1N1MT3n1MT4n1M0t1MT2n1 M0t2n65438+5438+0bm0t4an1bm0t4banynm0tn654438a1m0t1n/m0t2n1 M0t 3n 1M0IVB T4b Any NM0 IV C stage Any NM0N 1 Undifferentiated cancer All undifferentiated cancers belong to stage IV? Regional lymph node metastasis is common in stage IV thyroid carcinoma, including A T4a, any NM0 IV B T4b, any NM0 IV C and any NM 1 regional lymph node, but the prognosis of well-differentiated tumors (papillary carcinoma and follicular carcinoma) is not as significant as that of medullary carcinoma. Among cancer patients with different degrees of differentiation, the adverse effect of lymph node metastasis on prognosis is only seen in the older group. Metastatic lymph nodes at the first station are composed of parapharyngeal lymph nodes, paratracheal lymph nodes and Delphi lymph nodes, which are adjacent to the thyroid gland and located in the middle of the neck. They are usually described as group VI. Secondly, lymph nodes metastasized to the middle and lower groups of lymph nodes in internal jugular vein, supraclavicular lymph nodes, and (usually rare) upper groups of lymph nodes in internal jugular vein and upper groups of spinal accessory nerves. Submandibular and submental lymph node metastasis is rare. Upper mediastinal lymph nodes (group 7) are easy to metastasize before and after. In patients with extensive neck metastasis, retropharyngeal lymph node metastasis is often seen. Bilateral cervical lymph node metastasis is common. The structure of N classification is as follows: the first station (cervical center/sixth group) is N1a; ; And neck and/or upper mediastinum were n1b. Lymph node metastasis should also be described by grouping cervical fatigue lymph nodes. Although the lymph node metastasis of medullary carcinoma follows a similar pattern, its prognosis is very poor. For the accuracy of pN, the histological examination of selective neck dissection usually includes more than 6 lymph nodes, and the histological examination of radical neck dissection or modified radical total neck dissection usually includes more than 10 lymph nodes. If the number of lymph nodes is less than the above number, it will still be classified as pN0. Distant metastasis: distant metastasis circulates along the blood, such as lung and bone, and can also involve many other parts.