Synovial Sarcoma of the Temporomandibular Joint and Infratemporal Fossa: A Case Report.

Temporomandibular joint (TMJ) and infratemporal fossa (ITF) tumors, even though rare, present diagnostic complexities due to their nonspecific symptoms. Synovial sarcoma comprises 5-10% of adult soft-tissue sarcomas and is uncommon in the head and neck and exceptionally rare in the TMJ/ITF region. We presented a case of monophasic synovial sarcoma affecting the left TMJ/ITF in a 24-year-old man with severe preauricular pain who was misdiagnosed with temporomandibular disorder for 3 years. When in-depth evaluations uncovered a 40 mm tumor adjacent to the TMJ, extensive resection and immediate reconstruction were conducted, followed by postoperative radiotherapy and adjuvant chemotherapy. Magnetic resonance imaging photos of the early stage and after 3 years of tumor progression, initial signs and symptoms, and intraoperative images allowed tumor evolution assessment.