Simple Ranula

Epidemiology

A ranula is a cystic lesion arising in the floor of mouth that is believed to result from obstruction of the sublingual or minor salivary gland. The obstruction is most commonly thought to be congenital or posttraumatic in origin. The cysts develop from continued secretion of the mucous glands into an obstructed duct. Ranulas have also been referred to as mucoceles or pseudocysts in the floor of mouth. Although ranulas have been reported in all age groups, they are most common in children and young adults. There is no reported gender predilection.

Clinical Findings

There are two types of ranulas, simple and complex. A simple ranula is the most common form. By definition, simple ranulas are above the mylohyoid muscle and are confined to the sublingual space. They are usually paramedian and are situated in the vicinity of the sublingual gland. Simple ranulas present as submucosal SLS masses. They are typically pliable palpation on and exhibit a characteristic translucent, bluish hue (“frog belly” appearance). Ranulas may occasionally rupture, causing expulsion of viscid fluid into the oral cavity.

The diving ranula (plunging, complex) is believed by some to arise from rupture of a simple ranula. These lesions extend inferiorly below the level of the mylohyoid muscle either by extending over the free margin of the mylohyoid muscle or by passing directly through it. Diving ranulas present as a painless, fluctuant, soft tissue neck mass. The majority of diving ranulas are above the hyoid bone, although large lesions may extend into the thoracic inlet or mediastinum.