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

Abstract

Introduction: 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.

Presentation of case: 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.

Discussion: 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.

Conclusion: 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.

Keywords: Head and neck sarcoma; Immunohistochemistry; Intraosseous; Synovial sarcoma.

Fig. 1

Presurgical clinical view. A. Extraoral view. There is no evidence of swelling and discoloration of the skin. B. Intraoral view. An exophytic lesion was evident. The surface of the lesion was the same color as the mucosa, but red in some areas. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

Radiographic view. A. In the panoramic view a radiolucent lesion with an ill-defined margin in the left mandibular body, from the distal of second premolar to the distal of second molar, and from the alveolar crest to the upper border of the lower alveolar nerve canal, was evident. B. In the Cone CBCT view, perforation of the buccal cortex was evident in areas close to the alveolar crest.

Fig. 3

Histologic view. A. Photomicrograph showing cellular fascicles of spindle cells with interlacing growth pattern with mild nuclear pleomorphism (H&E stain ×200). B. Photomicrograph showing cellular fascicles of spindle cells with interlacing growth pattern with mild nuclear pleomorphism and mitotically active features (H&E stain ×400).

Fig. 4

Immunohistochemistry view. A. Photomicrograph showing the patchy cytokeratin (AE1/AE3) positivity in the tumor cells (×10). B. Photomicrograph showing strong BCL2 positivity in the cytoplasm of the spindle cells (×10). C. Photomicrograph showing diffuse expression of CD99 in the cytoplasm and cell membranes of the tumor cells (×10). D. Photomicrograph showing TLE1 diffuse nuclear positivity (×20).

Fig. 5

Post operation panoramic view. Treatment was carried out by a surgical resection of soft and hard tissues. The area was reconstructed temporarily with a titanium macro-plate.