A ranula is a pseudocystic lesion of the sublingual gland that is found in the floor of the mouth. A simple ranula is found above the level of the mylohyoid muscle and is usually the result of sublingual duct obstruction.
A plunging ranula refers to a pseudocyst that occurs with salivary duct rupture and is found below the level of the mylohyoid muscle. Diagnosis is based on a thorough history and physical examination, with imaging as an adjunct. Complete surgical excision, including the involved sublingual gland, is the treatment of choice.