Solitary Fibrous Tumor of the Masticator Space with Unusual Extension: a Case Report

Background: We present the case of a patient with solitary fibrous tumor of the masticator space with unusual extension. Case presentation: A 43-year-old woman presented with a painless mass with intraoral extension on the right cheek. The B-scan sonograph and magnetic resonance imaging revealed the extension of the tumor. The biopsy performed under local anesthesia raised the suspicion of a solitary fibrous tumor. Tumor excision included a preoperative tumor embolization. The surgical removal of the tumor included a partial parotidectomy on the right side, insertion of masseteric and temporalis muscle, resection of the middle part of the zygomatic bone and stabilization of the bone with a plate, mobilization of the tumor from the maxillary sinus and the pterygopalatine fossa through an endoscopic approach and an approach via partial resection of the anterior wall of the maxillary sinus after identifying and sparing the infraorbital nerve. Ôhe histological findings confirmed the diagnosis of solitary fibrous tumor. The patient's treatment completed with radiation therapy, and 2.5 years later, there was recurrence in the right temporal area. Conclusion:To our knowledge, this is the second reported case of solitary fibrous tumor arising in the masticator space and the only case with extension intraorally and in the paranasal sinuses. Tumor embolization and complete surgical excision are the most frequently recommended treatments.