Glottic tumors present early because voice changes occur early. Subglottic cancer is rare and often presents with airway obstruction because of the limited space at the level of the cricoid cartilage and bilateral vocal cord paralysis. Transglottic tumors extend from the vocal cord across the ventricle to the false vocal cord. The majority of these tumors are T3 or, since tumor in the ventricle can extend into nearby thyroid cartilage, T4. Transglottic tumors are more likely to metastasize than tumors limited to the glottis, and treatment of the neck is necessary when T3 or T4 tumors of the transglottic larynx present.
Evaluation begins in the office with assessment of vocal cord mobility.
This information, along with the extent of disease seen on flexible laryngoscopy, is necessary for staging. Direct laryngoscopy under general anesthesia is necessary to rule out a metachronous primary cancer, to obtain a biopsy, and to identify tumor boundaries. In cases where conservation surgery is contemplated, rigid 70-degree endoscopes can be passed through the laryngoscope to carefully examine the subglottic region and extension of tumor. A detailed knowledge of laryngeal anatomy is necessary to stage laryngeal cancer and to plan appropriate therapy. The supraglottic larynx consists of the epiglottis, aryepiglottic folds, arytenoids, false vocal cords, and preepiglottic space.