Sublingual Dermoid Cyst Mimicking Ranula on Imaging: Surgical Treatment and Outcome in a Human Immunodeficiency Virus (HIV)-Positive Patient.

Dermoid cysts are rare congenital lesions that arise due to the entrapment of ectodermal and mesodermal elements during embryonic development. We report the case of a 21-year-old male with HIV who presented with a longstanding sublingual mass associated with difficulty in chewing and swallowing. Clinical examination revealed a firm, non-tender, and mobile sublingual mass, accompanied by concurrent submental swelling. Ultrasonography and computed tomography of the neck were suggestive of ranula. The patient underwent surgical excision through an extraoral submental approach under general anesthesia. The cyst was found to be attached to the mylohyoid muscle and was carefully dissected and removed in its entirety. Histopathological analysis confirmed a dermoid cyst, showing stratified squamous epithelium lined by keratin and sebaceous glands. The patient's postoperative recovery was smooth, with no recurrence noted at the three-month follow-up. Although rare, dermoid cysts of the oral cavity should be considered in the differential diagnosis of midline sublingual swellings. Imaging modalities, including ultrasonography and computed tomography (CT), are integral for preoperative assessment, although they may occasionally present challenges in achieving a definitive diagnosis. Complete surgical excision is the definitive treatment, with the decision to use either an intraoral or extraoral approach based on the size and location of the cyst and the risk of infection. Early detection and treatment are vital to avoid complications like airway obstruction and difficulty swallowing.