Abstract
Synovial chondromatosis is a disease with cartilaginous metaplasia of the connective tissue in the synovial membrane, but reports of synovial chondromatosis in the temporomandibular joint (TMJ) are rare. Many reports of synovial chondromatosis in the region include images of calcification in the radiological imaging examination. However, it is difficult to diagnose the disease state in the case of an image without calcification. In this paper, we report that magnetic resonance imaging (MRI) and fine-needle aspiration cytology (FNAC) were useful for diagnosing synovial chondromatosis without calcification in radiological images. A 35-year-old woman was referred to our hospital with a slight preauricular swelling in the left TMJ region. The calcification image was not found in the region by orthopantography and computed tomography. The MRI revealed a low T1 signal and high T2 signal. The FNAC revealed that it was not chondrosarcoma or synovial sarcoma, but was highly suspicious of chondromatosis. When the left upper articular cavity was opened, there were many cartilaginous loose bodies, and so resection of all these bodies and synovectomy were performed under a diagnosis of synovial chondromatosis. Histological examination of the loose bodies demonstrated synovial chondromatosis. There has been no recurrence for 19 months after surgery.
