[Primary intraosseous squamous cell carcinoma of the mandible].

Primary intraosseous squamous cell carcinoma is an extremely rare tumor of the mandible. The diagnosis is based on the evidences showing that the tumor is neither originated from a distant metastasis of another primary tumor nor an invasive oral cancer. In this article, we report a 59-year-old female case with a medical history of ductal carcinoma of the breast, lichen planus, and rheumatoid arthritis who was admitted with complaints of a painful and swollen left lower jaw, and was surgically treated for primary intraosseous carcinoma of the mandible and with postoperative adjuvant radiotherapy.