Lymphoepithelial cyst located in the floor of the mouth: Report of a case.

Abstract

Lymphoepithelial cysts are usually found on the lateral region of the neck. Rarely, however, lymphoepithelial cysts can be found in the oral cavity. Here, we report a case of lymphoepithelial cyst located in the floor of the mouth, in a 57-year-old man. The patient complained of a painless swelling of the floor of the mouth. During the course of the first medical examination, a circumscribed oval mass was found in the floor of the mouth just at the right side of the lingual frenum, measuring approximately 9 x 8 mm. The clinical diagnosis was a cystic lesion. Under local anesthesia, the lesion was totally excised. Histologically, the cyst was lined with stratified squamous epithelium, and the surrounding area revealed large amounts of lymphoid tissue showing a various germinal center. The histopathological diagnosis was d lymphoepithelial cyst. There was no evidence of recurrence in the patient for 10 months after the operation.

An immunohistochemical study of a lympithelial cyst occurring on the ventral surface of the tongue.

“…Cysts of the oral cavity have mainly been reported in America and Europe while there have only been a few reports in Japan. The most common location of such cysts in the oral region is the floor of the mouth, but other sites including the ventral surface of the tongue, the soft palate, and rarely the palatoglossal fold, buccal mucosa and lips have also been described [1][2][3]. Thus, the present case, which occurred on the ventral surface of the tongue, is a relatively rare type.…”

“…Lymphoepithelial cyst, or so-called branchial cyst, is usually found in the lateral region of the neck. However, it rarely occurs in the oral region [1,2]. Although the histology of the lesion is characterized by an epithelial lining of lymphoid tissue within the cyst, no extensive immunohistochemical study has been done [3,4].…”