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.)