Of the cystic lesions, the lymphoepithelial cysts are being seen more and more commonly with the increase in AIDS patients being imaging. These cysts tend to be multiple and are often located in the parotid gland. They are often associated with multiple cervical lymph nodes. They tend to have sharp borders and appear similar to adenomas on non-contrast MR, but maintain cystic characteristics as they do not enhance.
The branchial cleft cyst can arise adjacent to the parotid gland, particularly if it is a second branchial cleft cyst, which has a propensity to arising near the angle of the mandible. However, the first branchial cleft cyst is more likely to be found within the parotid, as the remnant first branchial cleft extends from the submandibular triangle to the external auditory canal. First branchial cleft cysts are often located at the inferior aspect of the parotid, either in the superficial or deep lobe. They can also present as a mass at the external auditory canal. If branchial cleft cysts become infected, they can have an enhancing rim and mimic an abscess. They can also mimic a Warthin's tumor or even a mucoepidermoid carcinoma with central necrosis.
Potential cystic masses at the floor of the mouth in the vicinity of
the sublingual gland and submandibular glands also include ranulas, plunging
ranulas, sialoceles, dermoids, epidermoids, and thyroglossal duct cysts. Of these, the
thyroglossal duct cyst can be paramedian, but is rarely has any communication
with the sublingual or submandibular spaces. Retention cysts and simple
congenital cysts may also be found in the salivary glands, that are not
associated with the branchial apparatus or other congenital remnants.