PMC4601956_01
MRI of the right side TMJ. a: Sagittal PDWI (closed position). b: Sagittal PDWI (open position). c: Sagittal T2WI (closed position). d: Frontal PDWI (closed position). e: Frontal T2WI (closed position). A medium signal intensity area thought to be due to a mass lesion was observed in PDWI and expansion of the upper joint space was suspected (a, b, d, arrows indicate). Joint effusion with hypertrophy of the synovium with low signal intensity spots in the upper joint space was found on T2WI (c, e, arrows indicate).
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MRI revealed that the upper joint space was expanded, with joint effusion in which low signal intensity spots were apparent (Fig. 1a-e). Deformity and erosive changes were observed in the lateral part of the mandibular condyle, which was connected to a mass lesion, and the articular disc seemed to be perforated (Figs. 1 d, e and 2 b). These findings led to diagnosis of a tumor of the right side TMJ, which was strongly suspected to be synovial chondromatosis based on the MRI and arthrography findings for the upper joint space (Figs. 1 and 2).
Arthrography of the right side TMJ. a: Sagittal plane in the closed position. b: Frontal plane in the closed position. Fibrous adhesion was suspected (arrows indicate).
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Fibrous adhesion was suspected on arthrography (Fig. 2a and b). Deformity and erosive changes were observed in the lateral part of the mandibular condyle, which was connected to a mass lesion, and the articular disc seemed to be perforated (Figs. 1 d, e and 2 b). These findings led to diagnosis of a tumor of the right side TMJ, which was strongly suspected to be synovial chondromatosis based on the MRI and arthrography findings for the upper joint space (Figs. 1 and 2).
Intraoperative photographs (a-c) and the resected specimen (d).
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Surgery was performed through a temporo-preauricular incision (Figs. 3 a-d and 4 a ) and both upper and lower joint spaces were opened for observation.
Intraoperative findings. These illustrations are taken from the operative notes for this case. The annotations were translated into English by the author.
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Surgery was performed through a temporo-preauricular incision (Figs. 3 a-d and 4 a ) and both upper and lower joint spaces were opened for observation. The lesion was connected to the articular disc in the medial part of the joint space and adhered to the bone surface of the mid to lateral aspect of the mandibular condyle (Fig. 4b and c). The mass lesion was resected en bloc with the articular disc (Fig. 4b and c).
Pathological findings showed granulation tissue with peripheral vasodilation and inflammatory cell infiltration, including plasma cells and lymphocytes, in synovial tissues.
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