Pigmented villonodular synovitis of the temporomandibular joint: an extensive case with skull-base involvement.

Pigmented villonodular synovitis (PVNS) is a benign lesion of unclear etiology involving the synovial membranes of joints, bursae, and tendon sheaths. Its occurrence in temporomandibular joint (TMJ) is distinctly rare. Despite its benign nature, PVNS is locally destructive to the surrounding structures. Misdiagnosis and delay in diagnosis contribute to the frequency of tumors presenting at an advanced stage at the time of treatment. Thus, PVNS often requires extensive surgery. A case of PVNS of the left TMJ, involving the left infratemporal fossa and subtemporal cranial base, is presented herein. Preoperative computerized tomography, magnetic resonance imaging, and fine-needle aspiration biopsy were used to establish a presumptive diagnosis and to determine the extent of the lesion. Complete excision of the lesion through an infratemporal fossa approach has provided 7 years of a disease-free period with adequate preservation of function.