Mucocele

The soft “bubble” on the mucosal surface of a 42-year-old man’s lower lip had developed, disappeared for 3 months, and returned. The lesion caused no pain or discomfort. The lesion’s unique appearance and history is typical of a mucocele—a mucous retention cyst that is called a ranula when it occurs on the floor of the mouth or the underside of the tongue. The polyp can result either from a ruptured minor mucous salivary gland duct or from retention of mucus caused by an obstructed duct; trauma often triggers the cyst’s development. Virtually all mucoceles occur on the lower lip. These lesions are benign, pose no risk, and often disappear spontaneously; no treatment is necessary. However, when squamous cell carcinoma or plasmacellularis, which are in the differential, are suspected or if the lesion interferes with speech or swallowing, removal may be warranted. Mucoceles can be excised or marsupialized; however, recurrence is common. (Case and photograph courtesy of Joe Monroe, PA-C.)