Pigmented villonodular synovitis: dedicated PET imaging findings.

Pigmented villonodular synovitis (PVNS) is an uncommon entity, which has the potential to cause severe pain. The gold standard for evaluation is MRI, and previous PET findings associated with PVNS have only been documented in the setting of concurrent malignancy. In the setting of recurrent disease, PET is being used to evaluate prebiological and postbiological treatment responses. Recurrent PVNS demonstrates greater hypermetabolic activity than previously documented, supporting the case as a potential mimic of malignant/metastatic disease. Post-treatment evaluations demonstrate decreased metabolic activity, which suggests response to treatment. This behaviour further supports the contention that there is a neoplastic origin to PVNS.