TABLE 74-1 TNM Classification for Head and Neck Cancer (Except Nasopharyngeal)

TABLE 74-1 TNM Classification for Head and Neck Cancer (Except Nasopharyngeal)
PRIMARY TUMOR SITE
T Grade	Oropharynx	Hypopharynx
T1	0-2 cm	0-2 cm
T2	2.1-4 cm	>1 site, 2-4 cm
T3	>4 cm	>4 cm
T4a	Larynx, muscle of tongue, medial pterygoid, hard palate, mandible invasion	Thyroid/cricoid cartilage, hyoid bone, thyroid gland, esophagus, or central compartment soft tissue invasion
T4b	Lateral pterygoid muscle, pterygoid plates, lateral nasopharynx, or skull base or encases carotid artery invasion	Invasion of prevertebral fascia, encases carotid artery, or involves mediastinal structures
REGIONAL LYMPH NODES (N)
NX	Regional lymph nodes cannot be assessed
N0	No regional lymph node metastasis
N1	Unilateral metastasis in lymph node(s), ≤6 cm in greatest dimension, above the supraclavicular fossa
N2	Bilateral metastasis in lymph node(s), ≤6 cm in greatest dimension, above the supraclavicular fossa
N3	Metastasis in a lymph node(s) >6 cm and/or to supraclavicular fossa
	N3a > 6 cm
	N3b Extension to the supraclavicular fossa
MX	Distant metastasis cannot be assessed
M0	No distant metastasis
M1	Distant metastasis