Temporomandibular joint cyst as a preauricular mass

(Editorial Comment: The authors describe a rare entity that may mimic a common benign parotid neoplasm. The clinical presentation, work-up, and treatment are summarized.) Preauricular masses are usually parotid tumors. Rarely, they are temporomandibular joint cysts. These cysts are divided between ganglion cysts and synovial cysts. Twelve temporomandibular joint cysts have been reported. Eight have been ganglion cysts and 4 have been synovial cysts. 1 This is the 5th synovial cyst reported as a temporomandibular joint cyst. Treatment is uncertain; however, surgical excision of the temporomandibular joint cyst has the highest success rate. CASE REPORT A 47-year-old woman presented to the Ear, Nose, and Throat Clinic with a preauricular mass. She admitted to the mass growing slowly and being present for approximately 1 year. She had left preauricular pain and discomfort when chewing. The pain had become worse before her visit. She had a history of temporomandibular joint dysfunction and was being treated by her dentist. Her past medical history was basically unremarkable. Her physical examination showed a 2-cm mass in the left preauricular region. The mass was tender to the touch and mobile. There was no facial nerve paralysis or paresis. The rest of her head and neck examination was unremarkable. A fine-needle aspiration was performed. The results were nondiagnostic. Epithelial cells were obtained, but we could not make a diagnosis. She was offered an additional fine-needle aspiration, even with the use of ultrasound needle-guided aspiration, but she refused. Therefore, a computed tomography (CT) scan was obtained, which showed a cystic lesion near the parotid gland but did not involve the parotid gland (Fig 1). Because the pain was becoming unbearable and there was no diagnosis of this cystic lesion, she was offered surgery. She was taken to the operating room where a superficial parotidectomy was performed for exposure. The cystic lesion involved the left temporomandibular joint. The cystic lesion was removed, and the entire joint and capsule of the temporomandibular joint was reconstructed at the time of surgery. Pathological examination showed that this was a synovial ganglion cyst of the left temporomandibular joint. She was followed up in 1 week with no complications. She admitted her pain was gone. Postoperatively, she had no pain on chewing. Six months postoperatively, she only complained of occasional temporomandibular joint problems, which were very mild compared with her past history.