Unusual giant plunging sublingual epidermoid cyst: A case report and review of literature

Key clinical message: When treating a painless or asymptomatic mass in the submental or floor of the mouth, sublingual epidermoid cyst should be considered. Despite its irregularity, preventing malignant transformation is essential for a successful outcome.

Abstract: Dermoid and epidermoid cysts are rarely found in the head and neck region. They account for less than 0.01% of all oral cavity cysts. This is a rare case of a sublingual epidermoid cyst of the oral cavity in a 25-year-old male. The patient presented with a painless sublingual swelling for a duration of 1 month. The clinical examination revealed a non-tender swelling in the sublingual region extending to the submental triangle. Magnetic resonance imaging confirmed a 6.2 × 7.7 × 3.2 cm cystic lesion in the sublingual space. Fine needle aspiration cytology confirmed dermoid cyst contents. Intra-oral surgical excision under general anesthesia was performed successfully. Histopathological analysis revealed that the cyst wall was lined by stratified squamous epithelium. The presence of a prominent granular layer and keratin flakes confirmed the diagnosis of an epidermoid cyst. Postoperative recovery was good, and no recurrence was observed during follow-up. This case emphasizes the infrequent and unusual presentation of a case of a giant plunging sublingual epidermoid cyst and promotes awareness and potential studies in the enhancement of patient care in this area.