Laryngoceles are outpouchings of the mucous membrane of a part of the voice box (larynx).
Laryngoceles may bulge inward, resulting in hoarseness and airway obstruction, or outward, causing a visible lump in the neck. Laryngoceles are filled with air and can be expanded when a person breathes out forcefully with the mouth closed and the nostrils pinched shut. Laryngoceles tend to occur in musicians who play wind instruments.
On a computed tomography (CT) scan, laryngoceles appear smooth and egg-shaped. They may become infected or filled with mucus-like fluid and are usually removed surgically.