The paraglottic space and transglottic cancer: anatomical considerations.

Transglottic cancer of the larynx crosses the laryngeal ventricle and involves both the vestibular and vocal folds. It has been described to spread within the paraglottic space (PGS). This region of adipose tissue, containing blood vessels and nerves, immediately adjacent to the thyroid laminae, was originally defined by Tucker and Smith (1962). However, the precise topographic relationships of this clinically important space are still controversely discussed. Therefore, a reinvestigation was done in serial sections of 19 plastinated adult human larynges. Laterally, the PGS is bordered by the thyroid cartilage. Superomedially, the PGS is continuous with the preepiglottic space (PES) in most specimens. In some cases, the PGS and the PES are completely separated from each other by a conspicuous collagenous fiber septum. Small projections of the paraglottic adipose tissue extend between the fibers of the thyroarytenoid muscle. Inferomedially, the PGS is bordered by the conus elasticus. Anteroinferior extensions of the PGS escape the larynx beneath the inferior rim of the thyroid cartilage. Posteroinferiorly, the paraglottic adipose tissue extends between the intrinsic laryngeal muscles and towards the cricoarytenoid joint. Dorsally, the PGS is bordered by the mucosal lining of the piriform sinus. A precise knowledge of the topography of the PGS can explain typical symptoms and routes of spread of tumorous growth: extension toward the hypopharynx, extension into the anterior extralaryngeal tissues, invasion of the thyroid cartilage, impairment of vocal cord movements due to infiltration of laryngeal muscles or immobilization of the cricoarytenoid joint.