What is Mucocele and Ranula?
Mucoceles and ranulas are common issues affecting the saliva glands. A mucocele happens when the flow of saliva is disrupted in the smaller saliva glands. There are two types of mucoceles: extravasation and retention. The first kind, extravasation, usually happens because of an injury leading to saliva getting stuck in the tissue surrounding the gland. The second kind, retention, is less frequent and happens when the duct carrying the saliva gets blocked, causing saliva to accumulate in the duct.
Ranulas are a type of mucocele, but they originate from the larger saliva glands and appear on the floor of the mouth. These can also be divided into two types: oral ranulas and cervical or plunging ranulas. Oral ranulas form due to saliva leakage and build-up from the major saliva gland above certain neck muscles called the mylohyoid muscles. On the other hand, cervical or plunging ranulas happen when mucus collects along the tissues in the neck.
What Causes Mucocele and Ranula?
Mucoceles are a condition that happens when the small saliva glands in your mouth get injured. These glands are located all over the inside of your mouth, but are most commonly found in the lower lip. They can get injured in various ways, such as accidentally biting your lip while chewing. Other ways they can get injured include chronic inflammation or irritation (like from heat or smoking), damage to the exit tube of the gland, trauma during medical procedures such as intubation, and very rarely from stones formed in the saliva glands.
Ranulas are somewhat similar to mucoceles and they happen when the exit tube of the major salivary glands is damaged. This damage is often a result of trauma, but it can also be due to a blockage in the tube like a saliva stone or a mucus plug, which is less common. Other causes include chronic inflammation conditions like sarcoidosis and Sjogren syndrome, infections like HIV causing scarring around the tube, underdevelopment or narrowing of the tube, absence of the tube, and cancer. A difference in the anatomy of the saliva gland’s tube system might make people more prone to getting ranulas. This likelihood seems to be higher when the Bartholin tube (found in the sublingual gland under the tongue) connects and empties into the Wharton tube.
Risk Factors and Frequency for Mucocele and Ranula
Mucoceles, a type of blister that can develop in the mouth, occur in about 2.4 out of every 1000 people. This condition is most common in individuals between the ages of 3 and 20. Another similar condition, called a ranula, is even less common, occurring in just 0.2 out of every 1000 people. Like mucoceles, ranulas also tend to most often affect teenagers and young adults.
- Mucoceles and ranulas often form due to trauma such as lip biting.
- For mucoceles, the inner aspect of the lower lip is the usual spot, but they can develop anywhere inside the mouth.
- Other common spots for mucoceles include the soft palate, behind the molars, and the top of the tongue.
- Ranulas most often form on the floor of the mouth.
- More often than not, sublingual (under the tongue) glands are usually the source of ranulas.
- Ranulas may sometimes develop from the submandibular (under the jaw) gland, but this is rare.
It’s important to note that there’s no specific gender or race that’s more prone to these blisters; they can affect anyone equally.
Signs and Symptoms of Mucocele and Ranula
People who have mucoceles usually experience painless swelling in their mouths. These growths form quickly and may change in size. Often, mucoceles will disappear on their own after they rupture and the contents are absorbed by the mouth lining. Though they may develop after trauma, such as oral surgery or biting the tongue, many times there’s no obvious cause. The swelling typically last between 3 to 6 weeks, but in rare cases it can take days or even years to go away.
Oral ranulas are also characterized by painless swellings, but they appear in the floor of the mouth. These can impact speaking, swallowing, chewing, and in some instances even breathing because they push the tongue upwards and inwards. If the tongue applies pressure on the ranula, it can interfere with saliva flow, causing pain during eating or chewing.
Cervical ranulas, on the other hand, show up as painless lumps in the neck. These usually appear after a trauma to the floor of the mouth or a dental surgical procedure.
On physical examination, mucoceles look like dome-shaped, painless, mobile swellings that don’t turn white when pressure is applied. They usually range from 0.1-4 cm in size. Superficial mucoceles are bluish to transparent, while deeper ones have a pinkish color. About 80% of these growths occur on the lower lip, with less commonly affected areas including the floor of the mouth, under the tongue, the inner cheeks, and the palate.
Oral ranulas, meanwhile, look like large, blue to transparent cystic swellings in the floor of the mouth, similar to a frog’s belly. They are soft and don’t turn white when compressed. Cervical ranulas, or plunging ranulas, present as painless, mobile, expanding lumps in the neck. They are similar to oral ranulas in that they usually occur on one side, but can cross the midline.
Testing for Mucocele and Ranula
When it comes to diagnosing a mucocele (a lesion in the mouth caused by blockage or damage to a salivary gland) or an oral ranula (a similar condition that happens under the tongue), doctors usually base it on the condition’s symptoms. Even though imaging tests are not normally needed for these conditions’ evaluation, they can certainly assist in ruling out other possible causes, identifying the cause (for instance, stones), or determining the swelling’s size, which can guide any surgery that might be needed.
One imaging technique that can be used is ultrasonography. When performed by experts, high-resolution ultrasonography can identify stones, abscesses, cysts and can even accurately assess whether a tumor is harmless or cancerous up to 90% of the time. However, to evaluate vascular lesions, which are abnormalities in blood vessels, color doppler imaging is needed. This technology uses sound waves to measure blood flowing through a vessel.
Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) tests are not often required, but might be helpful in cases of a large plunging or cervical ranula (a swelling under the jawline or in the neck that has moved through a defect in the mylohyoid muscle, which is a muscle in the mouth). Likewise, they can help determine the extent of the swelling, which is essential to know before doing any surgery. Aside from these imaging exams, a biopsy might be necessary. A biopsy involves taking a small sample of tissue to check if the disease is benign (not harmful) or malignant (cancerous).
Treatment Options for Mucocele and Ranula
Mucoceles and ranulas are types of cysts that often go away on their own. However, if they last for a long time, cause symptoms, or don’t seem to be getting better, several treatment options are available:
Mucocele approaches:
1. Surgical Excision: If the mucocele keeps coming back, doesn’t get better, or causes symptoms, surgery to remove the mucocele and the related salivary gland can be done. This operation has a low chance of the mucocele coming back again.
2. Aspiration: Aspiration, or draining the mucocele with a needle, isn’t usually the best treatment because the mucocele often comes back. It’s mainly used to rule out other possible conditions before deciding on surgery.
3. Marsupialization: This procedure is used when the mucocele is large. It’s a way to remove the mucocele without removing a lot of tissue, which reduces the risk of complications from surgery. If marsupialization doesn’t work, the mucocele might need to be surgically removed. A specific approach for little kids with small mucoceles is micromarsupialization where a suture is used to create an opening for the mucocele to drain and heal.
4. Laser Ablation, Cryosurgery, and Electrocautery: These treatments use a laser, extreme cold, or electric current, respectively, to remove the mucocele. They’re usually used for mucoceles that are close to the surface.
Ranula approaches:
1. Surgical Excision: Taking out the ranula and the related large salivary gland through surgery is an effective treatment for both oral and cervical ranulas (ranulas in the mouth or neck). This treatment works well and usually means the ranula won’t come back.
2. Marsupialization: Some doctors choose to do marsupialization before considering surgery. In this procedure, the ranula is packed with gauze for 7 to 10 days which allows the cavity to heal and seals off the leakage site. This method can also cause the immune system to react to the gauze as if it were a foreign body, leading to fibrosis and atrophy (scar tissue and wasting away) of the offending acini (tiny sacs in the salivary gland). If marsupialization doesn’t get rid of the ranula, surgery might be necessary.
3. Laser Ablation, Cryosurgery, and Electrocautery: These techniques that use a laser, cold temperature, or electric current can be used for smaller ranulas either by themselves or before marsupialization.
4. Intralesional Injection of a Sclerosant Agent: This is an experimental method where an agent known as OK-432 (a preparation of bacteria) is injected into the ranula to try to treat it, but the success rates vary.
What else can Mucocele and Ranula be?
Mucoceles and ranulas are medical conditions that occur under the tongue and can often be mistaken for other problems. The list below showcases a number of conditions that doctors may need to rule out when diagnosing these issues:
- Hemangioma
- Lymphangioma
- Dermoid cyst
- Benign or malignant salivary gland neoplasm
- Lipoma
- Abscess
- Venous lake
- Fibroma
- Benign mesenchymal neoplasm
What to expect with Mucocele and Ranula
Overall, the outlook for conditions like mucoceles and ranulas is generally quite positive. Usually, these conditions show up as harmless, pain-free swelling in the mouth that doesn’t cause any other health problems. That being said, some bigger swellings might interfere with speaking, chewing, swallowing, or even breathing, depending on where they’re located.
If the entire swelling, along with the gland causing it, can be surgically removed, there’s a low chance that it will happen again. On the other hand, other procedures like making a small opening in the swelling or just drawing out the liquid inside it (also known as marsupialization and aspiration) are associated with a higher chance of the swelling returning.
Interestingly, in recent pediatric studies, the chance of the condition coming back after surgery ranged from 6%-8%.
Possible Complications When Diagnosed with Mucocele and Ranula
Some potential problems with mucoceles and ranulas are infection, the risk of bursting and then forming again, and difficulties with swallowing in case of a large ranula. Surgery may introduce some risks including:
- Bleeding during surgery
- Damage to the Wharton duct, leading to narrowing and obstructive inflammation in the salivary glands
- Harm to the lingual nerve, which could cause temporary or permanent numbness
- Damage to the marginal mandibular branch of the facial nerve, causing numbness
After the surgery, complications can include:
- Blood pool (hematoma)
- Infection
- Surgical wound reopening (dehiscence)
Failing to remove oral ranulas completely can result in half of the plunging or cervical ranulas. These enlarging ranulas may cause breathing problems or acute inflammation in the mediastinal area, which can be life-threatening.
Recovery from Mucocele and Ranula
After surgery, it’s best to stick to a diet of liquids, soft foods or bland items for a few days if you had a smaller procedure, or for a longer period if you had a major procedure like salivary gland removal.
As for physical activity, you should avoid heavy exercises for a time, which could range from a few days to a few weeks, depending on what kind of operation you’ve had.
Preventing Mucocele and Ranula
Patients should be aware that mucoceles and ranulas, which are types of mouth lesions, often resolve on their own. However, if the swelling causes problems with speaking, swallowing, or becomes infected, it’s essential to seek medical help. Certain oral habits, like lip biting, can cause these lesions. If this is the case, patients should be encouraged to stop these habits to prevent the formation of such lesions.
It’s also very critical for healthcare providers to discuss treatment options with patients. This includes information about the success rate and potential complications of each option. The goal is to choose what will benefit the patient the most. Patients also need to be aware that these mouth lesions can reoccur. Lastly, after any surgical intervention, patients should be taught to recognize signs and symptoms of a potential wound infection. If these signs appear, they should immediately seek medical attention.
