Fibromatosis of the infratemporal fossa extending to the parapharyngeal space accompanied by trismus

Fibromatosis is a tumor of fibroblastic origin that may arise in any musculoaponeurotic structure. Although fibromatosis is histologically benign, it has a tendency to invade surrounding tissues and often recur locally after treatment. A 34-year-old female patient was presented with pain in the left buccal region, left loss of visual acuity, and trismus. Computed tomographic scans revealed a large mass in the infratemporal fossa and parapharyngeal space. An open biopsy was performed and the pathological diagnosis was a fibromatosis. Surgical treatment for her trismus was performed simultaneously.