[Investigation on invasion of preepiglottic space by supraglottic carcinoma]

This study, based on analysis of 100 whole-organ serial sections of the larynx, concluded that preepiglottic space invasion is involved in 60% of supraglottic carcinoma. The preepiglottic space is involved either by invasion through the adjacent structures of the epiglottis, or more frequently by destroying the epiglottic cartilage and the thyro-epiglottic ligament. The preepiglottic space is involved mainly by epiglottic and epiglottic-ventricular carcinomas, accounting for 95% of carcinomas which invade the space. The involvement of preepiglottic space by supraglottic carcinoma is intimately related to the morphologic features, marginal growth patterns, and T classification. Ulcerative carcinoma is the commonest, accounting for 65%. The incidence of the infiltrative carcinomas is the highest. With increase in T stage, the percentage of invasion of preepiglottic space is increased. We believe that the easy invasion of the preepiglottic space by the supraglottic carcinoma is due to the fact that the epiglottic and epiglttic-ventricular carcinomas which account for 83% of supraglottic carcinomas are located in front of the larynx. In addition, the carcinoma easily destroys the epiglottic, cartilage and enters the preepiglottic space because the embryonic barrier which exists below the glottis and the perichondrium of the epiglottic cartilage is quite fragile.