Aggressive fibromatosis in the head and neck region: Benign tumor with often mutilating effects.

BACKGROUND Aggressive fibromatosis (AF) or desmoid tumor of the head and neck region is a rare, usually unresectable, benign soft tissue tumor with locally aggressive behavior. METHODS AND RESULTS A 31-year-old woman presented with a progressive trismus, a swelling in the retromandibular area, as well as loss of sensibility of the maxillary and mandibular branch of the trigeminal nerve. MRI of the head and neck revealed an infiltrative mass involving the masticator, parapharyngeal, and prevertebral and paravertebral space on the left with intracranial extension through the orbital fissure. After the fifth biopsy, 15 months after presentation, the diagnosis of AF was made. The tumor was unresectable, so intensity-modulated radiotherapy was given with curative intent using a total dose of 60 Gy in 30 fractions of 2 Gy. After 16 months, she showed progressive disease, for which tamoxifen 40 mg twice daily was started with a good response for 2 years. After that, she started with sorafinib, on which she has stable disease now. CONCLUSION The often long delay in proper diagnosis and the treatment challenges of a desmoid tumor are illustrated in this case. Furthermore, this article reviews the literature concerning AF, especially of the head and neck region.