Pigmented villonodular synovitis of the temporomandibular joint - computed tomography and magnetic resonance findings: a case report

Pigmented villonodular synovitis (PVNS) is a benign but locally aggressive and destructive disease originating in the synovial membranes. It is a proliferative disorder of unknown etiology. Involvement of the temporomandibular joint (TMJ) is very rare. Computed tomography clearly reveals areas of lytic bone erosion and sclerosis, and also clearly defines the extent of the tumor which is the focal areas of hyperdensity within the soft-tissue mass. Magnetic resonance images invariably show profound hypointensity on both T1-and T2-weighted sequences due to hemosiderin pigmentation. Additionally, high signal intensity on T2-weighted images may indicate cystic loculation of the joint fluid. This case study describes a rare case of PVNS of the TMJ with bone destruction of the mandibular condyle. Complete surgical excision of the lesion was performed through a preauricular approach with temporal extension. During the 10-year follow-up, two more operations were performed due to local recurrence and the fracture of the reconstruction plate. Total joint reconstruction with Biomet was finally performed, and the absence of disease was confirmed with a biopsy report showing fibrosis with hyalinization and mild inflammation of the excised soft tissue from the old lesion.