Mucocele of the oral cavity

by Jason Wasserman MD PhD FRCPC
February 16, 2023

What is a mucocele in the oral cavity?

A mucocele of the oral cavity, also known as a mucus cyst, is a noncancerous growth on the inside of the mouth. It is called a “mucocele” because it is filled with mucus. Mucoceles commonly involve the lips, inner cheeks, and floor of the mouth.

What causes a mucocele in the oral cavity?

Mucoceles in the oral cavity are typically caused by trauma such as biting. Other causes include blocked ducts, salivary gland stones, and chronic dry mouth.

What is inside a mucocele?

Mucoceles are filled with a sticky fluid called mucus.

Can a mucocele in the oral cavity turn into cancer over time?

No. A mucocele in the oral cavity is a benign (noncancerous) growth that will not turn into cancer over time.

How is this diagnosis made?

Your doctor may suspect that you have a mucocele after examining your mouth. In some cases, the diagnosis is made after the mucocele is surgically removed and the tissue will be sent to a pathologist for examination under the microscope.

What does a mucocele from the oral cavity look like under the microscope?

When examined under the microscope, a mucocele looks like a round open space surrounded by inflammatory cells called histiocytes. Pathologists use the term cyst or cystic-lesion to describe this space. Other types of inflammatory cells such as lymphocytes and plasma cells may also be seen. In cases where the mucocele has ruptured (broken up), specialized inflammatory cells called multinucleated giant cells also be seen.

mucocele oral cavity
This image shows a mucocele in the oral cavity. The mucocele appears as a round open space. A small amount of blue mucus can be seen inside the mucocele on the right side of the image.
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