Temporomandibular joint synovial cysts: A systematic review of the literature and a report of two cases.

Temporomandibular joint (TMJ) synovial cysts are rare, unlike peripheric locations like the wrist or the knee. They share similar presentations with ganglion cyst, benign and sometimes malignant lesions. Only histopathological analysis confirms diagnosis in some cases, finding a true cyst lined by synoviocytes containing synovial fluid. They seem to be related to an increased articular pressure following trauma. In this study we present two cases of TMJ synovial cyst and a systematic review of the literature. A total of 32 cases were retrieved from published literature in PubMed, Cochrane Library and ClinicalTrials.gov databases using the search terms 'TMJ synovial cyst', 'temporomandibular synovial cyst', 'jaw joint synovial cyst'. Swelling (91.3%) and pain (78.3%) were the most common symptoms. MRI was the most commonly used imaging modality that was found to be beneficial for diagnosis. In almost all cases the cyst was removed under general anesthesia, allowing histopathological examination. Only two patients still had pain after removal of the cyst. No recurrence was observed .