Solid type primary intraosseous squamous cell carcinoma in the maxilla: report of a new case

BACKGROUND: Primary intraosseous squamous cell carcinoma is a rare jaw bone tumor defined as squamous cell carcinoma arising within the jaw, having no initial connection with the oral mucosa and developing from residual odontogenic epithelium or from an odontogenic cyst or tumor. Solid type of this tumor arising in the maxilla is an even rarer presentation, because the majorities derive from cystic lesions and are found in the posterior mandible. CASE PRESENTATION: A 36-year-old Japanese man was referred to our clinic with a complaint of pain around the anterior maxillary region on the right side. Intraoral examination identified a firm, non-fluctuant mass with no ulceration in the vestibular region of teeth #11-13. Incisional biopsy was performed, leading to histological diagnosis of moderately differentiated squamous cell carcinoma. Contrast-enhanced computed tomography revealed a destructive tumor with no cystic lesion, >50 mm in diameter. There was no evidence of metastatic disease on chest radiography, upper gastric endoscopy or positron emission tomography. Based on these findings, solid type primary intraosseous squamous cell carcinoma was diagnosed. The patient underwent tumor ablative surgery. The surgical defect was reconstructed using a partially double-folded free radial forearm flap and prefabricated denture-based surgical obturator. The postoperative course was quite good. Neither recurrence nor metastasis had been found as of 3 years and 1 month postoperatively. CONCLUSION: To the best of our knowledge, the present case represents only the 10th case of solid type primary intraosseous squamous cell carcinoma arising in the maxilla to be reported.