Diagnosis and Prognostic Implications of Primary Intraosseous Carcinoma: A Case Report and Literature Review

Primary Intraosseous Carcinoma (PIOC) is a rare and aggressive squamous cell carcinoma (SCC) derived from remnants of odontogenic epithelium with no initial connection to oral mucosa. Due to the rarity of the disease, etiology and epidemiology are not clearly defined. The most affected site is the posterior mandible, and clinical features include swelling of the jaw, jaw pain, and sensory disturbances. Given the similarities of PIOC to other odontogenic carcinomas, diagnosis is often difficult, resulting in delays in intervention. Treatment of PIOC of the mandible includes surgery alone, surgery with adjuvant radiotherapy or chemotherapy, and free flap reconstruction. PIOC prognosis is poor, with the lymph nodal status acting as an important indicator. We present a case of a 60-year-old female who presented with a left submandibular mass initially thought to be SCC of unknown primary origin. Further investigation led to a final diagnosis of PIOC of the mandible. Clinical, radiological, and histological features of PIOC will be discussed.