Synovial Cyst of the Temporomandibular Joint: A Case Report and Review of the Literature

Synovial cysts of the temporomandibular joint are rare benign periarticular lesions that are clinically and radiologically difficult to distinguish from ganglion cysts. A 41-year-old woman presented with a 1-year history of right preauricular swelling. Magnetic resonance imaging (MRI) demonstrated a well-defined crescent-shaped T2-hyperintense cystic lesion on the lateral surface of the right mandibular condyle. The lesion was completely excised through a preauricular approach under general anesthesia. Histopathological examination showed multiple cystic spaces lined by cells morphologically consistent with attenuated synoviocytes and a fibromyxoid stromal wall. Immunohistochemical staining was not performed. The patient remained recurrence-free at 1 year. This case highlights the value of MRI for preoperative localization, the importance of histopathological assessment for diagnosis, and the role of complete excision in symptomatic, diagnostically uncertain lesions. Long-term follow-up is advisable because recurrence data remain limited.