A mucous cyst, also known as a mucocele, presents as a fluid-filled swelling that commonly appears on the lip or inside the mouth. These cysts form when the mouth’s salivary glands become blocked with mucus, or when trauma to the oral cavity, such as lip or cheek biting, causes a salivary gland to rupture. Mucous cysts are benign and painless, appearing as soft, smooth, round, dome-shaped lesions that can be clear, bluish, or pink in color. They range in size up to 1 centimeter in diameter, though some can be larger.
The Natural Course of Mucous Cysts
Mucous cysts often resolve without intervention, particularly smaller, superficial ones. This natural resolution occurs when the cyst ruptures, allowing the accumulated mucus to drain and the area to heal. Some individuals may experience multiple mucous cysts over time, or a cyst might disappear and then reappear later.
These cysts commonly arise in areas prone to minor trauma, such as the inner surface of the lower lip, inner cheeks, tongue, or the floor of the mouth. They can also form on the fingers near the fingernail at the distal interphalangeal (DIP) joint, often linked to underlying osteoarthritis.
The time it takes for a mucous cyst to resolve can vary significantly, ranging from a few days to several weeks or even months. While many cysts do go away, this outcome is not guaranteed for every individual. Factors such as the cyst’s size, its exact location, and the underlying cause can influence whether it will spontaneously regress or persist. It is advised not to pick at or attempt to pop the cyst, as this can create an open wound, increasing the risk of infection or permanent scarring.
When to Seek Professional Advice
While many mucous cysts resolve on their own, there are circumstances when seeking professional medical advice becomes important. If a cyst causes pain, discomfort, or interferes with daily functions like chewing, swallowing, or speaking, it warrants medical attention. Large cysts, especially those on the floor of the mouth (known as ranulas), can affect speech, chewing, swallowing, and in rare cases, even breathing, requiring prompt evaluation.
Rapid growth of a cyst or changes in its appearance or size are also reasons to consult a healthcare provider. Cysts that frequently recur, or those showing signs of infection such as increased redness, swelling, or pus, require professional assessment to prevent complications. Additionally, if there is any uncertainty about the diagnosis or if the lesion appears unusual, a doctor can diagnose and rule out more serious conditions.
Managing Persistent Mucous Cysts
For mucous cysts that do not resolve naturally or cause ongoing problems, healthcare professionals can offer various management approaches. One common method involves draining the cyst. Cryotherapy, which uses extreme cold, is another effective option. Laser treatment precisely removes the cyst.
In cases where cysts are persistent, large, or frequently recur, surgical excision may be recommended. This procedure involves cutting out the cyst, and sometimes the salivary gland that caused the cyst may also be removed to prevent recurrence. For digital mucous cysts, surgical removal has a low recurrence rate. Steroid injections into the cyst can also be used to reduce inflammation and promote healing.