ranula

Ranula is a mucous extravasation cyst of the floor of the mouth that typically arises from the sublingual gland. It is usually considered a pseudocyst, lacking an epithelial lining, formed when mucin leaks into the surrounding tissues after duct obstruction or rupture of the sublingual gland.

There are two main forms. Simple (oral) ranula presents as a blue, fluctuant swelling on the floor of the mouth and may cause tongue elevation or discomfort. Plunging (diving) ranula extends through the mylohyoid into the neck, producing a neck mass and often with little or no intraoral involvement.

Diagnosis relies on clinical examination supported by imaging and aspiration. Ultrasound or MRI helps delineate extent and differentiate ranula from cystic lesions or vascular malformations. Fine-needle aspiration yields viscous, mucinous content but is not diagnostic on its own.

Treatment is typically surgical. The definitive approach is complete excision of the ranula together with the sublingual gland, usually via a transoral route for simple ranula or a combined/transcervical approach for plunging lesions. Marsupialization alone has higher recurrence rates. In selected cases, sclerotherapy (e.g., with OK-432) may be considered as an alternative or adjunct. Recurrence is more likely if the sublingual gland is not removed.

Prognosis is generally good after complete gland excision, though recurrence can occur if residual gland tissue remains. Ranula most commonly affects children and young adults, with a higher incidence in females in some series.