A large sublingual epidermoid cyst with parapharyngeal space extension: A case report

INTRODUCTION: Epidermoid and dermoid cysts in the floor of the mouth are uncommon. A large cyst can lead to functional morbidities including airway, swallowing and speech problems. The treatment of choice is surgical excision. To obtain a good result, the decision for optimal surgical technique is valuable. CASE PRESENTATION: A young female patient presented with a slowly growing mass at the submandibular area and swelling in the floor of mouth. The MRI showed large sublingual cyst extended posteriorly to the parapharyngeal space. She underwent surgical excision of the cyst size 6.5 × 3.2 × 2.5 cm via an intraoral approach. The pathological examination revealed a benign stratified squamous epithelium-lined cyst with no evidence of adnexal structure consistent with an epidermoid cyst. The patient remained disease-free after two years of follow-up. DISCUSSION: Generally, large sublingual cysts over 6 cm located or transgress below the mylohyoid muscle are removed by an extraoral approach. Our team reported the first case of a large lateral sublingual epidermoid cyst with parapharyngeal extension removed by an intraoral approach. Preoperative imaging is important for surgical approach selection. CONCLUSION: Successful management of sublingual epidermoid cyst extended to the parapharynx is feasible by an intraoral approach with excellent functional and cosmetic outcomes.