Squamous cell carcinoma emerging in an orthokeratinized odontogenic cyst: A case report and brief review

Carcinomatous transformation of the epithelial lining of an odontogenic cyst (OC) is rare. However, such malignancies may represent 1–2% of all carcinomas seen in some Oral and Maxillofacial Pathology diagnostic services. Most instances have been reported in association with residual/periapical cysts and dentigerous cysts. There have been a few well-documented cases of carcinoma arising in an odontogenic keratocyst (OKC). The following report describes a rare case of squamous cell carcinoma arising from an orthokeratinized odontogenic cyst (OOC) of mandible in a 30 year old male. Clinical and radiological examinations were indicative of an OC of the mandible. Histologically, the cystic lesion composed of orthokeratotic cystic epithelial lining and well-differentiated squamous cell carcinoma, showing continuity between them without a connection to the oral mucosa was evident. This report reveals the malignant potential of OOC, which is reported to have little clinical aggressiveness.