New barriers to ventricular invasion in paraglottic laryngeal cancer.

BACKGROUND

Anatomic barriers to the spread of laryngeal cancer include the conus elasticus, the quadrangular membrane, and the thyroid cartilage. It has been speculated that an elastic barrier surrounds and protects the ventricle.

METHODS

The authors studied the microanatomic patterns of spread of 17 cases of patients who had laryngeal cancer with paraglottic disease and confirmed their findings by examining normal autopsy specimens.

RESULTS

Five patients of the seventeen cases showed no ventricular mucosal involvement despite extensive paraglottic disease. Both an inner, central, subepithelial periventricular elastic membrane barrier were identified; the latter was in continuity with the conus elasticus and quadrangular membrane.

CONCLUSIONS

Two weak fibroelastic barriers surround the ventricle. The outer, peripheral, fibroelastic membrane is contiguous with the conus elasticus and the quadrangular membrane. Therefore, ventricular involvement is not a sensitive indicator of paraglottic spread. Squamous cell cancer may grow around the periventricular barriers to involve both the true and false cords but may spare the ventricle. The prognostic significance of the violation or preservation of the periventricular elastic barriers is unknown.