The cyst of the salivary gland is called mucocele. Mucocele is a swelling that is caused by of accumulation of saliva in the salivary duct. This accumulation is caused because of obstruction or trauma to the duct of the salivary gland.

There are two types of mucocele

• Retention type –it is caused because of obstruction of the salivary gland caused because of a tumor, sialolith (calcified salivary stone) resulting in accumulation of saliva in the duct.
• Extravasation type –it is caused due to laceration in the minor salivary gland. (laceration of the gland is caused due to trauma). Trauma may be caused by biting the lip, or cheek or in cases where the lip or cheek gets pinched during a surgical procedure. This trauma leads to extravasation of mucin leading to inflammation of that area.

Features of a mucocele

• Extravasation cyst is more common than retention type.

The extravasation type 

usually occurs in the lower lip and 

• tongue.
• Retention type is usually seen in the palate, cheek, and floor of the mouth. 
• They are painless swellings but have a high chance of recurrence.
• Mucocele can be either superficial or deep.
• Superficial mucoceles have a bluish translucency and are fluctuant.
• These swellings can be easily ruptured since they have a thin wall.
• Their size varies from 4mm to 1 cm.
• Deep mucocele has the color of the normal mucosa and are firm swellings.
• This type of mucocele increases and reduces in size periodically.

Treatment

Surgical excision of the mucocele . But even after surgical excision, the recurrence rate is high.