A Case of Synovial Sarcoma of the Parapharyngeal Space

Abstract

Synovial sarcomas occur primarily in the periarticular region and are predominantly located in the extremities. However, they can arise in the head and neck region. In the available Japanese literature, only 14 cases have been reported. We encountered a rare case of synovial sarcoma of the parapharyngeal space. Thus, we report this case with some consideration according to literature. The patient was a 15-year-old male with no clinical symptoms. Swelling of the right mesopharynx and soft palate was noted by his general practitioner at school. From the initial examinations of CT, MRI, Gallium-67 citrate scan and FNA, a malignant tumor of the parapharyngeal space with no metastasis was revealed. Then, an excisional biopsy was performed and the pathological diagnosis was SYNOVIAL SARCOMA (biphasic type). After the biopsy, the tumor rapidly spread to the oral cavity. Therefore, embolization of the right maxillary artery was performed to reduce the blood supply to the tumor. After the tracheostomy, radical surgery was performed using the mandibular swing maneuver, which enabled us to approach the tumor. Complete en-bloc resection of the tumor was carried out.
During the operation, there was no significant association between the tumor and the mandibular joint. After the operation, adjuvant chemotherapy and radiotherapy were to be applied, but we were unable to obtain informed consent. Therefore, we decided to apply only radiotherapy (total 60Gy) on an out-patient basis. Although he has been alive and disease free for 8 months, it is necessary to check for local recurrence and lung metastasis regularly. Although the prognosis of the disease is not good, we can overcome this disease by means of cytogenetic therapy in the future.