Mucocele

The soft "bubble" on the mucosal surface of a 42-year-oldman'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 typicalof a mucocele--a mucous retention cyst that is called a ranulawhen it occurs on the floor of the mouth or the undersideof the tongue. The polyp can result either from a rupturedminor mucous salivary gland duct or from retentionof mucus caused by an obstructed duct; trauma often triggersthe cyst's development. Virtually all mucoceles occuron the lower lip.These lesions are benign, pose no risk, and often disappearspontaneously; no treatment is necessary. However,when squamous cell carcinoma or plasmacellularis,which are in the differential, are suspected or if the lesioninterferes with speech or swallowing, removal may bewarranted. Mucoceles can be excised or marsupialized;however, recurrence is common. (Case and photograph courtesy of Joe Monroe, PA-C.)