Giant plunging ranula: a case report
A 21-year-old woman visited our department complaining of a large painless swelling in the left submandibular region. The swelling had been recognized at its sudden onset two months earlier. Intraorally, her mouth floor was bluish and elevated. On palpation, the swelling revealed a soft, painless, and fluid-containing mass. The patient had no traumatic or surgical history, and the swelling did not cause difficulty in swallowing or speaking. Routine blood tests and the thyroid profile were within normal limits.\nPanoramic radiograph revealed no pathological changes. Contrast-enhanced computed tomography (CT) scan demonstrated a large rim-enhanced fluid attenuation mass occupying both sublingual spaces with an anterior connection (). The lesion extended into the left parapharyngeal space superiorly and compressed the left submandibular gland inferiorly (). Anteriorly, it extended to the right sublingual space in a horseshoe shape (). At the lower level of the lesion, several linear septa were noted (). A fluid-fluid level, which is the interaction between two fluids with different viscosities, was also noted (). Although the septation and fluid-fluid level within the lesion made the differential diagnosis from a cystic hygroma difficult, considering the location of the lesion in the sublingual space, it was diagnosed as a plunging ranula.\nUnder general anesthesia, an incision was made in the left lingual vestibule, and excision of the lesion along with extirpation of the left sublingual gland was performed. At surgery, the cystic lesion was found to be filled with a viscous and yellowish mucous fluid. After removal of the left sublingual gland, a cut-down tube was inserted into the middle portion of the left Wharton's duct.\nThe histopathologic examination of the specimen from the sublingual gland revealed ruptured acinar cells (). The patient made an uneventful recovery. The cut-down tube inserted into the left Wharton's duct was removed after 2 weeks. The patient has not experienced a recurrence 6 months postoperatively.