Primary Intraosseous Squamous Cell Carcinoma Derived from Odontogenic Cyst: Case Report and Review of 56 Cases

Primary intraosseous squamous cell carcinoma derived from odontogenic cyst is an uncommon lesion and was designated as odontogenic carcinoma by the World Health Organization. About 60 welldocumented cases of this disease have been reported between 1938 and 2001. This report is of a patient with squamous cell carcinoma arising in a dentigerous cyst in the body of the left mandible. The patient presented with a bony hard swelling with slight pain. Panoramic radiography exhibited a well-defined unilocular radiolucent area with an embedded left lower second premolar. Treatment included wide excision, radical neck dissection, and radiotherapy. Histopathologically, a transitional zone from the cystic epithelial lining to the well-differentiated squamous cell carcinoma was demonstrated. A review of 56 cases of intraosseous squamous cell carcinomas from previous reports is also included.