Primary chondromyxofibroma originating from the temporomandibular joint: A case report of an extremely rare benign bone tumor

Chondromyxoid fibroma (CMF) is an extremely rare cartilaginous tumor, accounting for less than 1 % of benign bone tumor. Most CMFs are found in the metaphysis of long bones. This study aimed to present a patient with temporomandibular joint (TMJ)-CMF involving pterygopalatine space and the skull base, and to discuss its epidemiology, clinical characteristics and management thereof. A 56-year-old Chinese Han woman visited our hospital with a chief complaint of facial asymmetry and progressive limitation of mouth opening due to this mass expanding upwardly to the auriculotemporal region. A computed tomography presented the wormlike osteolysis of the right condylar head presenting with swelling, cloudy flocculent ground-glass opacity, relatively clear boundary, thin bone in the middle of the cranial fossa, low continuity, and involving the temporomandibular joint. Incisional biopsy confirmed a diagnosis of TMJ-CMF. Using digital technique to determine the boundary of the lesion and reconstruct the normal glenoid fossa, the temporalis myofascial flap was transplanted between titanium mesh and condyle so as to reconstruct the disk after complete resection of the tumor. The patient's facial profile is symmetrical, with a mouth opening of 45 mm; there was no local recurrence, no complications such as cerebrospinal fluid fistula and cerebral hernia during 1-year follow-up period. To date, a review of the literature yielded only one case occurred in the TMJ was previously evaluated by radiology. To our knowledge, this is the second case of primary CMF in the TMJ.