A rare intraosseous synovial sarcoma of the mandible: A case report

Synovial sarcoma is a relatively common high-grade soft-tissue sarcoma. This lesion accounts for 5-10 % of soft-tissue sarcomas, which tend to appear in the limbs, especially the lower limbs. Synovial sarcoma in the neck is rare and causes involvement of the head and neck in 6-7 % of cases. Intraosseous involvement of the mandible is rare. In this report, a rare intraosseous synovial sarcoma of the mandible is reported.

A 29-year-old man with a complaint of painless outgrowth of the gingiva in the posterior region of the left mandible. In the intraoral examination, an exophytic, firm, smooth and well-defined lobulated mass on the alveolar ridge, extending from distal of the second premolar to mesial of the second molar, was observed. On a radiographic examination, a radiolucent lesion with an ill-defined border was seen in the left body of the mandibular with perforation of the buccal cortex. In a histological examination, immunohistochemistry confirmed synovial sarcoma. The patient underwent surgery with wide margins, and radiotherapy after surgery.

The main treatment method is surgery with a wide margin. Radiotherapy as an adjuvant treatment along with surgery is the second most common treatment method. Radiotherapy is recommended in cases of involvement of the margin of the lesion, size greater than 5 cm, and recurrence of the lesion. Chemotherapy after surgery has been used less frequently.

Surgical resection with a wide margin is the main treatment. Adjuvant radiation therapy and chemotherapy can be helpful in tumor control, especially in monophasic cases.