Plunging ranula: an unusual multilocular presentation.

A 32-year-old male patient who was HIV positive presented at the Wits Oral Health Centre complaining of a large swelling of the left submandibular region of three years' duration. The swelling was nontender, soft and doughy on palpation and appeared to be crossing the midline. Bilateral submandibular and submental lymphadenopathy was present. Intraorally the lesion caused considerable elevation of the floor of the mouth and impaired the flow of saliva. Fluid from the lesion was aspirated and the patient sent for MRI examination. These images revealed a multilocular cystic lesion causing disruption of the mylohyold muscle. The aspirate consisted of a thick, bloody fluid which tested positive for salivary amylase. A provisional diagnosis of plunging ranula was made. The multilocular nature of the lesion seen on MRI prompted a more extensive surgical approach in order to prevent recurrence. Consequently the sublingual gland was removed via an intraoral approach while the multilocular cyst was dissected by means of a submandibular approach in order to effect complete removal. Microscopic examination of the submitted specimen confirmed the clinical diagnosis of a plunging ranula.