Diffuse tenosynovial giant cell tumor in the temporomandibular joint area in a Chinese population: a clinicopathological analysis of 32 cases

Objectives: To analyze the clinicopathological characteristics of diffuse tenosynovial giant cell tumor (D-TGCT) in the temporomandibular joint area in a Chinese population. Methods: A total of 32 cases of D-TGCT in the temporomandibular joint area were collected, and their clinicopathological characteristics were analyzed; follow-up was performed for all patients. Results: Among the 32 patients, the male to female ratio was 1:1.13, with an average age of 42 years. Patients experienced symptoms of joint and ear pain and headache to varying degrees. Imaging studies showed lesions centered on the temporomandibular joint. Microscopically, the tumor tissue was composed of synovium-like monocytes, small histiocytoid cells and multinucleated giant cells; 53% (17/32) of cases showed lesions migrating with the synovium and articular disc, and 44% (14/32) of cases had differing levels of cartilaginous metaplasia in the lesions. All 32 patients underwent extended surgical resection, and recurrence occurred in 11% of patients with primary disease. Conclusions: In D-TGCT of the temporomandibular joint, synoviumlike monocytes show characteristics of semi-circular pigment in the cytoplasm; lesions often migrated with the synovium and articular disc. In the pathological diagnosis, clinical and imaging data should be considered together, and lesions containing giant cells near the temporomandibular joint should be differentiated.