title: Pseudotumor in the temporomandibular joint: A case report.
abstract: BACKGROUND
  Neoplastic disease in the temporomandibular joint (TMJ) is a rare condition and is difficult to differentiate from temporomandibular disorders (TMD) based on symptoms and simple X-ray examinations. Potential differential diagnoses include synovial chondromatosis and pseudotumor, both of which are also relatively rare in the TMJ.
  
  
  METHODS
  We report a case of pseudotumor of the TMJ that was difficult to differentiate from synovial chondromatosis in a 71-year-old woman with a chief complaint of pain in the left TMJ. MRI of the right TMJ initially led to diagnosis of synovial chondromatosis. Extirpation of the lesion was performed under general anesthesia. Histopathological findings of the resected specimen revealed inflammatory granulation tissue without cellular atypism.
  
  
  CONCLUSIONS
  The pathological findings for the resected specimen were compatible with pseudotumor of the TMJ. These findings were not supportive of synovial chondromatosis or other tumor diseases.
  
  
  CONCLUSIONS
  This case illustrates the importance of careful examination of a mass lesion in the TMJ for differentiation from other TMJ-related diseases.
authors: Department of Maxillofacial Surgery, Graduate School, Tokyo Medical and Dental University, Japan. Electronic address: h-yoshitake.mfs@tmd.ac.jp.
authors: Hiroyuki
authors: H
authors: Yoshitake
authors: Department of Oral Pathology, Graduate School, Tokyo Medical and Dental University, Japan.
authors: Kou
authors: K
authors: Kayamori
authors: Department of Maxillofacial Surgery, Graduate School, Tokyo Medical and Dental University, Japan.
authors: Ryosuke
authors: R
authors: Nakamura
authors: Department of Maxillofacial Surgery, Graduate School, Tokyo Medical and Dental University, Japan.
authors: Sou
authors: S
authors: Wake
authors: Department of Maxillofacial Surgery, Graduate School, Tokyo Medical and Dental University, Japan.
authors: Kiyoshi
authors: K
authors: Harada
keywords: Pseudotumor; Synovial chondromatosis; Temporomandibular joint