Tehran University Medical Journal

Background: Primary intraosseous squamous cell carcinoma (PIOC) of the mouth is a very rare but well-known carcinoma. It is locally invasive and its prognosis is quite poor. It may originate from the walls of an odontogenic cyst or de novo from the remnant epithelium at this region. Because the early symptoms of such malignancies are sometimes similar to those of inflammatory or periodontal diseases, early diagnosis is the most important step toward appropriate treatment.
Case Presentation: The case was a 46-year-old female with a sudden luxation of two posterior mandibular molars referred to a general dentist in May 2019. With diagnosis of periodontitis, the teeth were extracted without finding the cause of the tooth luxation. After four months, because of pain, swelling and non-healing socket of extracted teeth she referred to the department of Oral medicine in Mashhad Faculty of Dentistry. The patient was healthy with no systemic disease, drug history or familial history of cancer and no history of trauma, habits, tobacco, alcohol, and smoking. ln clinical examination, a nodular swelling with extensive ulcer and rolled borders along with hyperkeratosis and erythema on the posterior part of the right mandibular ridge was observed. The Extraoral examination revealed a tender mobile lymph node in the right submandibular region. After radiographic evaluation, with an initial diagnosis of SCC originated from the socket of extracted mandibular molars, incisional biopsy was performed, and histopathological analysis of the specimen revealed a primary intraosseous squamous cell carcinoma (grade II) and then necessary treatments (surgery, radiotherapy, chemotherapy) were performed.