Pigmented Villonodular Synovitis of the Temporomandibular Joint: A Case Report and Literature Review

Objective: Pigmented villonodular synovitis (PVNS) is a benign proliferation of tissues within a joint. It most frequently affects large joints but it is rarely diagnosed at the temporomandibular joint (TMJ). Radical excision with wide margins is the most accepted treatment modality. PVNS is resistant to radiotherapy. Herein we report a case involving the TMJ causing pain and trismus and its management that appears to be successful. Study Design: A case report Methods: A 74 year old female presented to our clinic complaining of a right pre-auricular mass that she noticed for a couple of years. The mass was growing slowly and never bothered her till recently. She started to have pain with jaw opening. Also, trismus became more pronounced. CT-neck with intravenous contrast showed an enhancing mass surrounding the right mandibular condyle, with expansion of the temporomandibular joint. CT-guided biopsy of the right TMJ confirmed the diagnosis of PVNS. Results: Patient underwent tracheostomy, right superficial parotidectomy followed by right condylectomy and partial mandibulectomy. Intraoperatively, the tumor was destroying the condyle and invading the meniscus, masseter and pterygoid muscles and extending medially toward the skull base. Histologically, PVNS-diffuse type was confirmed in the specimen with negative margins. Postoperatively, patient developed a transient facial paralysis while pain and trismus disappeared. Conclusions: PVNS is a rare lesion in the TMJ. Pre-auricular mass is the most common presenting symptom. CT-guided biopsy along with CT-neck is crucial in the workup. Resection of the lesion with wide margin is the recommended treatment. Facial paralysis is a complication of the surgical treatment but it is usually shortly-lived.