Ganglion Cyst of the Temporomandibular Joint: Case Report and a Review of the Literature

Background/Objectives: Ganglion cysts of the temporomandibular joint (TMJ) are rare, benign periarticular pseudocysts that are clinically indistinguishable from the true synovial cyst and frequently mimic parotid or other preauricular tumors, making preoperative diagnosis difficult. The aim of this report is to describe the diagnosis and surgical management of a ganglion cyst of the TMJ and to review the literature on the etiology, clinical presentation, treatment modalities, and outcomes of these lesions. We report a case managed with excision and review the published literature. Methods: We describe a 48-year-old woman with a slowly enlarging, painless left preauricular tumor managed by preauricular excision with intraoperative facial-nerve monitoring and provide a narrative review of ganglion and synovial cysts of the TMJ (PubMed/MEDLINE, Scopus and Google Scholar, searched from database inception to July 2026; histologically confirmed cases were extracted and tabulated). Results: Computed tomography showed mild condylar hypertrophy and a well-defined, non-enhancing fluid-density lesion (~15 HU; 15 × 10 × 7 mm) lateral to the condyle and abutting the anterior wall of the external auditory canal. The lesion was excised through a preauricular approach, with intraoperative facial-nerve stimulation. Histopathology showed a fibrous-walled cavity devoid of epithelial or synovial cell lining, with negative cytokeratin and CD31 confined to vascular endothelium, confirming a ganglion and excluding a vascular malformation. Facial-nerve function, mouth opening, and occlusion were preserved. Control magnetic resonance imaging at 17 months and clinical follow-up at 21 months showed no recurrence. Conclusions: Preauricular excision with facial-nerve preservation is the treatment of choice. Although recurrence is uncommon, documented recurrences several years after excision argue for longer, imaging-based follow-up.