Primary synovial sarcoma involving the submandibular gland

Abstract

Synovial sarcoma represents 5.6%-10% of all soft-tissue sarcomas. Adolescents and young adults are most frequently affected, mainly in the deep soft tissue of the extremities. Only 10% of synovial sarcomas affect the head and neck region; most of these are biphasic. We describe a case of an 18-year-old man who complained of a mass in the right submandibular region that had been present for approximately 12 months. On surgical removal, microscopic analysis showed a tumor formed by sheets of malignant spindle cells involving the submandibular gland. Immunohistochemistry displayed positivity for AE1/AE3, CK18/8, epithelial membrane antigen, CD99, CD56, and TLE-1. Based on these immunohistochemical and histopathologic features, a diagnosis of monophasic synovial sarcoma was rendered. The patient was treated with adjuvant radiotherapy and after 1 year was free of disease. To the best of our knowledge, this is the first reported case of synovial sarcoma involving the submandibular gland.