Soft Tissue Neck / Ranula

Figure (a) Axial T2 weighted MRI shows a high signal lesion in the left sublingual space extending to the submandibular space consistent with a plunging ranula (arrow). (b) Axial T1 weighted MRI with gadolinium enhancement of the same ranula showing minor rim enhancement of the cystic lesion (arrow)


MRI Coronal STIR and MRI T2 Sag images





A Ranula is a type of mucocele found on the floor of the mouth and usually involves the major salivary glands. Ranulas occur as a result of trauma or obstruction to the salivary gland excretory duct and spillage of mucus into the surrounding soft tissues. These lesions are divided into two types: oral ranulas and cervical or plunging ranulas. Oral ranulas are secondary to mucus extravasation that pools around the mylohyoid muscle, and the cervical or plunging ranulas are associated with mucus extravasation along the fascial planes of the neck.

A Ranulla looks like a bluish cyst located below the tongue. The cyst may fill the mouth and raise the tongue. Typically theses cysts are painless masses that do not change in size in response to chewing, eating, or swallowing. Ranulas tend to be relatively painless with little or no associated morbidity or mortality. Depending on the size and location, some ranulas may interfere with normal mastication.

Plunging ranulas can manifest as neck swelling in conjunction with, or independent of a ranula cyst on the floor of the mouth. Most reported plunging ranulas are 4 to 10 centemeters in size and are usually found in the submandibualr space. They have been reported to extend into the submental region, the contralateral neck, the nasopharynx up to the skull base, the retropharynx, and even into the upper mediastinum. Oral and plunging ranulas may affect swallowing, speech, or mastication and may result in airway obstruction. The very thoracic ranula may compromise respiratory funtion and may be life threatening.

Ranulas usually occur in children and younger adults. The cervical or plungling varient tends to occur a little later in life.

CT scanning is used to diagnose Ranulas, however MRI scanning is the most sensitive imaging study to evaluate the sublingual gland and its pathologic states. Many Ranulas resolve on their own and do not require surgical intervention. Medical therapy with medication is also a form of treatment. However if there is an airway obstruction or some sort of feeding problems, surgery is indicated.