Primary de novo intraosseous carcinoma of the mandible--report of a case and review of literature.

Primary intraosseous carcinoma (PIOC) is a rare malignant odontogenic neoplasm defined as squamous cell carcinoma arising within thejaws, having no initial connection with the oral mucosa and presumably developing from the residues of the odontogenic eptihelium. A 37yr old male patient reported with the complaint of pain and swelling in the right mandible and inability to open his mouth for the past six months. Examination revealed an expansile mass that involved the right mandible and extended from the 1st premolar region to the right angle of the mandible. The alveolar ridge was markedly expanded and was covered with intact, normal appearing mucosa. Radiographic examination revealed an ill-defined radiolucent area in the right body of the mandible, which extended to the lower border. Histopathologic examination revealed a well differentiated keratinizing squamous cell carcinoma. PIOC has no specific histopathologic features and can be definitively diagnosed only upon fulfillment of various criteria. These criteria were followed in our case and reported here for its rarity.