Ranula: Clinical Features, Diagnosis, and Management
Ranula: Clinical Features, Diagnosis, and Management
Ranula
A ranula is a type of mucocele that occurs in the floor of the mouth, named for its resemblance to a frog’s translucent underbelly (“rana”: Latin for frog). It arises from the sublingual gland, often due to trauma, obstruction, or anatomical variations affecting salivary flow.
Etiology and Pathogenesis
Ranulas are typically caused by:
- Trauma to the ducts of Rivinus of the sublingual gland, leading to salivary extravasation into adjacent tissues.
- Ductal obstruction or aneurysmal dilation may also contribute.
- The sublingual gland’s continuous secretion (unlike the parotid and submandibular glands that rely on gustatory stimulation) prevents healing by fibrosis, thus allowing mucus to accumulate.
Ranulas are most common in the second decade of life and show a female predilection. A genetic predisposition has been suggested, particularly in Asian populations. Anatomic variations in sublingual gland ductal architecture may also influence development.
Types of Ranula
Ranulas are classified into three main types:
| Type | Description |
|---|---|
| Oral Ranula | Confined to the sublingual space. Also termed “simple” or “superficial.” |
| Plunging Ranula | Extends below the mylohyoid muscle, presenting as a neck swelling. |
| Mixed Ranula | Exhibits both intraoral and cervical components. |
Plunging ranulas arise when mucus escapes through or around the mylohyoid muscle, tracking into the submandibular or cervical spaces.
Clinical Presentation
- Oral ranulas appear as:
- Painless, fluctuant, movable swellings on the floor of the mouth.
- Often lateral to the lingual frenulum.
- Bluish hue may be present in superficial lesions.
- Deeper lesions may present with normal-colored mucosa.
- Larger ranulas can displace the tongue and affect speech or eating.
- Plunging ranulas present as soft neck swellings, typically in the submandibular triangle, without intraoral signs in some cases.
Diagnosis
- Oral ranulas are often diagnosed clinically due to their characteristic appearance.
- Imaging is indicated to rule out other cystic lesions or when plunging is suspected:
- Ultrasound: Preferred for oral ranulas.
- CT with contrast or MRI: Recommended for evaluating plunging ranulas.
- Fine needle aspiration (FNA): May aid in confirming the cystic nature of the lesion.
Differential diagnoses include:
- Thyroglossal duct cyst
- Dermoid/epidermoid cyst
- Cystic hygroma
- Salivary gland neoplasms
Treatment and Management
✅ Definitive Treatment
- The most effective method for preventing recurrence is removal of the sublingual gland:
- Oral ranula: Intraoral excision of the sublingual gland and the ranula.
- Plunging ranula: Intraoral sublingual gland removal combined with cervical drainage.
⚠️ Alternative Treatments (Higher recurrence rates):
- Marsupialization (surgical unroofing)
- Simple excision of the ranula
- Sclerotherapy with OK-432 (a streptococcal-derived agent)
- Silver nitrate injections
- Botulinum toxin (BoNT) injections
❗Recurrence rates:
- Marsupialization: ~67%
- Excision of ranula alone: ~58%
- Sublingual gland removal: ~1%
💡 Observation
- Some ranulas, especially smaller lesions, may resolve spontaneously.
- Observation for up to 6 months may be considered in select cases.
Postoperative Considerations and Complications
- Recurrence is closely related to the completeness of sublingual gland removal.
- Potential complications include:
- Damage to Wharton’s duct
- Tongue sensory disturbances
- Infection, hematoma, or scarring
Conclusion
Ranulas are benign but potentially recurring lesions of salivary origin. Accurate diagnosis, thorough assessment of lesion extent, and selection of the appropriate surgical approach—ideally including sublingual gland excision—are key to successful long-term management. Emerging treatments like sclerotherapy and BoNT injections are promising alternatives in select patients.
