AGGRESSIVE FIBROMATOSIS IN THE MANDIBULAR ANGLE

Fibromatosis is a benign locally aggressive spindle cell neoplasm that rarely affects the oral and perioral tissues. A 16-year-old adolescent boy was referred because of a swelling in the right mandibular angle lasting 1 month and progressive difficulties in mouth opening lasting 8 months. Regional examination showed a swelling in the right mandibular angle covered by normal skin and limited mouth opening. Panoramic radiograph and computed tomography revealed multilocular radiolucent lesion in the right mandibular angle. Clinical diagnosis included aneurysmal bone cyst, nodular fasciitis, and myxoma. Because of the location of the lesion, it was removed under general anesthesia with per-surgical frozen analysis. Provisional frozen diagnosis was a benign spindle cell neoplasm, and histologic and immunohistochemical analysis of the surgical specimen confirmed the diagnosis of aggressive fibromatosis. The patient has been followed up with no signs of local recurrence.