Epidermoid cysts are common cystic lesions in the skin, ovaries, and testicles, but their occurrence in the oral cavity is uncommon. They consist of cysts delimited by a fibrous capsule without cutaneous annexes and are lined by stratified squamous epithelium. The differential diagnosis includes ranula, dermoid cysts, and lingual thyroid. Despite their benign presentation, these cysts can cause functional limitations, requiring special clinical attention for extensive lesions located in regions that preserve vital structures. This paper aims to report a case of epidermoid cyst in patient with swallowing and breathing difficulty, highlighting the clinical and surgical planning. © 2015 Ciro Dantas Soares et al.2015 Yilmaz, I., Yilmazer, C., Yavuz, H., Bal, N., Ozluoglu, L.N., Giant sublingual epidermoid cyst: A report of two cases (2006) Journal of Laryngology and Otology, 120, p. E19Tsirevelou, P., Papamanthos, M., Chlopsidis, P., Zourou, I., Skoulakis, C., Epidermoid cyst of the floor of the mouth: Two case reports (2009) Cases Journal, 2 (12), p. 9360Smirniotopoulos, J.G., Chiechi, M.V., Teratomas, dermoids, and epidermoids of the head and neck (1995) Radiographics, 15 (6), pp. 1437-1455Yasumoto, M., Shibuya, H., Gomi, N., Kasuga, T., Ultrasonographic appearance of dermoid and epidermoid cysts in the head and neck (1991) Journal of Clinical Ultrasound, 19 (8), pp. 455-461Chidzonga, M.M., Shija, J.K., Congenital median cleft of the lower lip, bifid tongue with ankyloglossia, cleft palate, and submental epidermoid cyst: Report of a case (1988) Journal OfOral and Maxillofacial Surgery, 46 (9), pp. 809-812Jayade, B.V., Upadya, V.H., Gopalkrishnan, K., Shirganvi, M.S., Epidermal inclusion cyst of the mandible after extraction of a third molar: Case report (2012) British Journal of Oral and Maxillofacial Surgery, 50 (5), pp. e72-e74Aggarwal, S.L., Meena, K., Ali, S., Thomas, S., Squamous cell carcinoma arising in epidermal inclusion cyst of breast: A diagnostic dilemma (2015) Breast Disease, 35, pp. 25-27Ziadi, S., Trimeche, M., Hammedi, F., Squamous cell carcinoma arising from an epidermal inclusion cyst: A case report (2010) North American Journal of Medical Sciences, 2 (1), pp. 46-47Mirza, S., Fadl, S., Napaki, S., Abualruz, A., Case report of complicated epidermoid cyst of the floor of the mouth: Radiology-histopathology correlation (2014) Qatar Medical Journal, 2014 (1), pp. 12-16Baliga, M., Shenoy, N., Poojary, D., Mohan, R., Naik, R., Epidermoid cyst of the floor of the mouth (2014) National Journal of Maxillofacial Surgery, 5 (1), pp. 79-83Anderson, S., Stassen, L.F., Case report: Sublingual epidermoid cyst in an elderly patient (2014) Journal of the Irish Dental Association, 60 (2), pp. 90-93Verma, S., Kushwaha, J., Sonkar, A., Kumar, R., Gupta, R., Giant sublingual epidermoid cyst resembling plunging ranula (2012) National Journal of Maxillofacial Surgery, 3 (2), pp. 211-213Jham, B.C., Duraes, G.V., Jham, A.C., Santos, C.R., Epidermoid cyst of the floor of the mouth: A case report (2007) Journal of the Canadian Dental Association, 73 (6), pp. 525-528Makos, C., Noussios, G., Peios, M., Gougousis, S., Chouridis, P., Dermoid cysts of the floor of the mouth: Two case reports (2011) Case Reports in Medicine, 2011. , Article ID 362170, 6 pagesPalaskar, S., Garde, J., Bartake, A., Narang, B., Teratoid cyst of the oral cavity: A rare entity (2014) Journal of Oral AndMaxillofacial Pathology, 18 (3), pp. 469-471Fernando, H.R., Pollan, L.D., Zhou, Z., Floor of mouth mass (2013) Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 116 (3), pp. 270-274Agarwal, A.K., Kanekar, S.G., Submandibular and sublingual spaces: Diagnostic imaging and evaluation (2012) Otolaryngologic Clinics of North America, 45 (6), pp. 1311-1323Ural, A., Imamoglu, M., Işik, A.U., Neckmasses confined to the submental space: Our experience with 24 cases (2011) Ear, Nose AndThroat Journal, 90 (11), pp. 538-540Patil, K., Mahima, V.G., Malleshi, S.N., Sublingual epidermoid cyst: A case report (2009) Cases Journal, 2 (9), p. 8848Bhatt, V., Evans, M., Malins, T.J., Squamous cell carcinoma arising in the lining of an epidermoid cyst within the sublingual gland-A case report (2008) British Journal of Oral and Maxillofacial Surgery, 46 (8), pp. 683-685