Diffuse Tenosynovial Giant Cell Tumor Around the Temporomandibular Joint: An Entity With Special Radiologic and Pathologic Features

Diffuse tenosynovial giant cell tumor (TGCT) of the temporomandibular joint (TMJ) is rare. The aim of the present study was to summarize the clinical, radiologic, and pathologic features of this tumor. Nine cases of TGCT in the TMJ region were examined. All available radiologic and pathologic documents were carefully reviewed. These cases were grouped into 3 types according to the radiologic features: bone-centered type, intraosseous type, and soft tissue type. Cases reported in the literature were reviewed to better summarize the clinical characteristics. TGCTs in the TMJ region showed some special radiologic and pathologic features. Radiologically, the lesion could be centered in the craniofacial bone or centered in the surrounding soft tissue. Four cases were categorized as the bone-centered type, 1 was categorized as the intraosseous type, and 4 were categorized as the soft tissue type. Pathologically, epithelioid mononuclear cells with abundant eosinophilic cytoplasm and eccentric nuclei were observed in all cases. Chondroid metaplasia was noted in 8 cases. Some areas were similar to giant cell reparative granuloma and chondroblastoma. All patients who underwent complete tumor resection showed no evidence of recurrence at follow-up. Of the 93 reported cases, only 5 developed postoperative recurrence and distant metastasis. TGCTs of the TMJ region share similar radiologic and pathologic features as other tumors, which indicates the TGCT might be a special entity within a spectrum of diseases.