What is the pathophysiology and treatment of a ranula?

Pathophysiology and Treatment of Ranula

The definitive treatment for ranula is transoral excision of the ipsilateral sublingual gland with ranula evacuation, which yields the lowest recurrence and complication rates. 1

Pathophysiology

Ranulas are pseudocysts that develop in the floor of the mouth due to:

• Extravasation of mucus from the sublingual gland or minor salivary glands following trauma or obstruction of the salivary ducts 2, 1
• Formation of a mucus-containing cavity lined by granulation tissue rather than epithelium (pseudocyst) 1
• Two main types: oral (simple) ranulas confined to the floor of the mouth, and plunging ranulas that extend below the mylohyoid muscle into the neck 1, 3

Diagnosis

• Clinical presentation typically includes a bluish, translucent swelling in the floor of the mouth that resembles a frog's belly (hence the name "ranula" from Latin "rana" meaning frog) 2, 1
• Physical examination reveals a fluctuant, non-tender mass that may interfere with speech, mastication, or swallowing depending on size 1
• Imaging (ultrasound, CT, or MRI) may be helpful for plunging ranulas to determine the extent of the lesion 1, 3

Treatment Options

Conservative Management

• Observation for spontaneous resolution (particularly in infants and children) for up to 5-6 months 2, 4
• Aspiration of mucus contents - high recurrence rate of up to 82% 1
• Sclerotherapy with OK-432 (Picibanil) - moderate recurrence rate of approximately 49% 1

Surgical Management

1. Marsupialization Techniques:

   • Conventional marsupialization - unroofing the cyst and suturing the edges to oral mucosa 5
   • Modified marsupialization - suturing the edges of the pseudocyst before unroofing 5
   • Micromarsupialization - passing sutures through the ranula without excision 3
   • Recurrence rates: 25.8% for conventional and 12% for modified marsupialization 5

2. Excision Procedures:

   • Ranula excision alone - higher recurrence rates 1
   • Sublingual gland excision with ranula evacuation - lowest complication rate (3%) and recurrence rate 1, 3
   • Combined sublingual and submandibular gland excision - unnecessary in most cases 1

3. Approach for Plunging Ranulas:

   • Intraoral approach - excision of sublingual gland and evacuation of ranula contents 1, 3
   • Transcervical approach - may be necessary for extensive plunging ranulas 1, 3
   • No significant difference in cure rates between approaches, but intraoral approach tends to have fewer complications 3

Treatment Algorithm

1. For infants and small children:

   • Initial observation for 5-6 months for possible spontaneous resolution 2, 4
   • If persistent, consider aspiration or marsupialization as temporary measures 2
   • Definitive treatment with sublingual gland excision when the child is older (around 1 year) if recurrence occurs 2

2. For older children and adults:

   • Simple oral ranulas: Transoral excision of the sublingual gland with ranula evacuation 1, 3
   • Plunging ranulas: Intraoral approach for sublingual gland excision with ranula evacuation when possible; transcervical approach for extensive lesions 1, 3

3. For recurrent ranulas:

   • Complete excision of the sublingual gland if not previously removed 1
   • Ensure identification and preservation of the submandibular duct (Wharton's duct) and lingual nerve during surgery 2, 4

Complications and Their Prevention

• Recurrence - most common complication (63% of all complications), minimized by complete sublingual gland excision 1
• Lingual nerve injury - can cause tongue hypesthesia (26% of complications) 1
• Bleeding/hematoma (7% of complications) - careful hemostasis during surgery 1
• Wharton's duct injury (1% of complications) - careful dissection and identification of the duct 1, 4
• Postoperative infection (3% of complications) - appropriate perioperative antibiotics 1

Special Considerations

• In infants, a more conservative approach is initially recommended due to the possibility of spontaneous resolution 2
• Identification of the submandibular duct and lingual nerve is crucial before removing the sublingual gland to prevent complications 2, 4
• For superficial oral ranulas, modified marsupialization may be considered as a less invasive alternative with acceptable recurrence rates 5