Staging malignancies of larynx

Supraglottis:
T1 - confined to one subsite
T2 - more than one subsite or glottis involvement without fixed cord or outside supraglottis, i.e., base of tongue, vallecula, medial wall of pyriform sinus
T3 - Fixed cord and/or invasion of post cricoid area, preepiglottic tissue, paraglottic space, thyroid cartilage inner cortex erosion
T4a - Invasion of thyroid cartilage and/or invasion beyond larynx, i.e., trachea, extrinsic tongue muscles, strap muscles, thyroid gland, esophagus
T4b - Invasion of prevertebral space, carotid artery encasement, mediastinal structures

Glottis:
T1a - Limited to one cord
T1b - Limited to both vocal cords with or without involvement of anterior or posterior commisure with normal cord mobility
T2 - supra and/or subglottic extension, and/or impaired cord mobility
T3 - Fixed cord and/or paraglottic space extension and/or thyroid cartilage inner cortex erosion
T4a - Invasion through thyroid cartilage and/or invasion beyond larynx, i.e., trachea, extrinsic tongue muscles, strap muscles, thyroid gland, esophagus
T4b - Invasion of prevertebral space, carotid artery encasement, mediastinal structures

Subglottis:
T1 - Limited to subglottis
T2 - Extends to vocal cord (s) without fixed cord
T3 - Vocal cord fixed
T4a - Invasion of cricoid ot thyroid cartilage and/or invasion beyond larynx, i.e., trachea, extrinsic tongue muscles, strap muscles, thyroid gland, esophagus
T4b - Invasion of prevertebral space, carotid artery encasement, mediastinal structures