Monophasic synovial sarcoma in the temporomandibular joint region: A case report and review of the literature.

Introduction And Importance: Synovial sarcoma is a malignant neoplasm that arises from soft tissue and makes up 5 % to 10 % of all types of sarcoma. It is most common between the ages of 15 and 40; it typically develops in the lower extremities; just 3 % to 10 % of cases arise in the head and neck. The usual main areas in the head and neck are the parapharyngeal, hypopharyngeal, and paraspinal.

Case Presentation: An 18-year-old woman presented with a painful mass in the left pre-auricular area.

Clinical Discussion: Magnetic resonance imaging showed a well-defined lobular mass localized superior and anterior to the left ear. Incisional biopsy showed spindle cell sarcoma. A preauricular incision was done to remove the tumor with the superficial lobe of the parotid gland during the procedure, and histological examination revealed a high-grade spindle cell sarcoma the differential diagnosis included a monophasic synovial sarcoma. Immunohistochemistry was done for a full evaluation and the panel supported diagnosing a monophasic synovial sarcoma.

Conclusion: Synovial sarcoma is a malignant tumor that is rare to develop in the temporomandibular region, which makes it a significant challenge to diagnose and differentiate it from other lesions, it should be considered in all patients with a mass in this region. The cornerstone to identify synovial sarcoma is Immunohistochemistry (IHC), and molecular genetic analyses. Total surgical excision, with or without radiation and chemotherapy, is currently the best option for treatment. We present a review of the literature after the case presentation.