Update on current diagnosis and management of anaplastic thyroid carcinoma

Table 2 T classification in tumor-node-metastasis system for anaplastic thyroid carcinoma of American Joint Committee on Cancer and Union for International Cancer Control 8^th edition

T	Size	Extension
T1	≤ 2 cm	Limited into thyroid
T1a	≤ 1 cm	Limited into thyroid
T1b	> 1 cm and ≤ 2 cm	Limited into thyroid
T2	> 2 cm and ≤ 4 cm	Limited into thyroid
T3	> 4 cm	Limited into thyroid or extrathyroid macroscopic invasion only of thyroid muscles and subcutaneous tissue
T3a	> 4 cm	Limited into thyroid
T3b	Any size	Extrathyroid macroscopic invasion only of thyroid muscles and subcutaneous tissue
T4	Any size	Macroscopic invasion of major adjacent structures
T4a	Any size	Macroscopic invasion of larynx, trachea, esophagus, recurrent laryngeal nerve
T4b	Any size	Macroscopic invasion of carotid artery, major vessels in mediastinum, prever-tebral fascia