Pigmented Villonodular Synovitis Masquerading as Metastasis on PET Imaging

Abstract

Pigmented villonodular synovitis (PVNS) is a metaplastic process that can occur in the synovium, bursae or tendon sheaths and can be localized or diffuse. Its features on radiographs and computed tomography are nonspecific, but magnetic resonance imaging is diagnostic. Its appearance on fluorodeoxyglucose (FDG) positron emission tomography (PET) is not well described. We present a case of recurrent squamous cell carcinoma of the floor of the mouth with an FDG-avid lesion of the left upper arm on a whole-body PET scan that was shown to be PVNS on subsequent biopsy. To our knowledge, this is one of the very few cases reported in the literature describing FDG avidity of PVNS. We explore the features of PVNS on various imaging modalities and its potential for being mistaken for malignancy.




J Med Cases. 2014;5(4):253-255
doi: http://dx.doi.org/10.14740/jmc1691w