Tumorlike Pigmented Villonodular Synovitis With Atypical Location: Appearance on 3-Phase 99mTc-MDP Bone Scan.

Pigmented villonodular synovitis (PVNS) is a proliferative disorder of unknown etiology that originates from the synovial membranes of joints. Some PVNS lesions have been misdiagnosed as malignancy due to their tumorlike imaging findings. There are few reports of PVNS on nuclear 3-phase bone imaging. However, 3-phase Tc-MDP bone scan can offer additional information about the dynamic flow features of the lesion, which may do help in differential benign and malignant. The present report describes 3-phase bone imaging in a surgically proven case of PVNS with tumorlike appearance and atypical location.