Unilateral Lymphoepithelial Cyst in the Tonsil: A Rare Clinical Condition and Review of the Literature

Abstract Lymphoepithelial cyst (LEC) is a benign cystic lesion that can grow anywhere within the lymphoid tissues of the head and neck region (both intraoral and extraoral sites), such as the parotid gland, submandibular gland, neck, and oral mucosa. Among these two groups, intraoral LECs are rare, comprising less than 1% of all oral cavity lesions. The intraoral LECs have been commonly reported on the floor of the mouth and the tongue, accounting for 88.3% of all cases. The occurrence of LEC in the tonsil is extremely rare, only a few cases have been reported in the literature. Generally, LEC is a benign disease, but it has a tendency for malignant transformation if not diagnosed and treated adequately. We presented a 31-year-old man with an abnormal sensation in his throat. Examination revealed right-sided tonsillar enlargement with a solitary cystic mass on it. A tonsillectomy was performed, and histological analysis confirmed the diagnosis. LEC is rare; its occurrence in the tonsil should be considered while evaluating a unilateral tonsillar mass. A detailed clinical evaluation and meticulous histological analysis are required to arrive at an accurate diagnosis. Our case report is unique because no recurrence or malignant transformation was noticed after follow-up.