Background: Primary intraosseous carcinoma is a rare neoplasm of odontogenic origin. The World Health Organization defines it as a squamous cell carcinoma (SCC), usually arises inside the jaw bones and having no connection with the oral mucosa. This lesion is documented with low incidence and unfavourable prognosis. PIOC occurred mainly in older age group with potent preference to males. In this study we presented this case to add that unusual clinical presentation of this lesion to the current literature. This case showed this malignant tumour commonly known for its unfavourable behaviour and aggressiveness documented with in unusual radiographic presentation that mimics periapical cyst.
Case Presentation: An old-aged heavy smoker male patient was admitted to Cairo University dental hospital with a complaint of painful swelling in his right posterior area of the mandible, started 4 months ago. Intra-oral examination revealed a swelling in the lower right posterior area in relation to the non-vital lower molars. A panoramic x-ray showed a well-defined radiolucent lesion apically to roots of lower right posterior teeth. An incisional biopsy was performed and the microscopic examination was done. The final diagnosis was confirmed to be primary intraosseous carcinoma.
Conclusion: Reporting this case could add to the existing literature about adding primary intraosseous carcinoma in list of D.D of any intrabony lesion regardless its size, extension and radiographic margins. This would help clinicians to early detection and improve survival rate of such affected patients.