Synovial chondromatosis of the right side temporomandibular joint extending to the middle cranial fossa: A case report with 7-year postoperative follow up and expression of a biomarker of cell proliferative activity.

INTRODUCTION:Synovial chondromatosis of the temporomandibular joint (TMJ) with cranial extension is rare. Here, we report 7-year follow-up of a case with immunohistochemical examination of cell proliferative activity. PRESENTATION OF CASE:The patient was a 72-year-old man. Severe bone resorption of the glenoid fossa was apparent on CT images. Pathological findings by biopsy led to diagnosis of synovial chondromatosis of the right side TMJ. Extirpation of the tumor was performed via temporopreauricular incision under general anesthesia. PCNA expression was examined by immunohistochemical analysis. The lesion had penetrated into the middle cranial fossa, but the cranial dura mater was intact. Expression of PCNA was confirmed. DISCUSSION:The PCNA expression suggested that growth activity caused expansion of the lesion to the skull base. CONCLUSION:We were able to follow up this case for a long period without recurrence postoperatively.