Tophaceous Gout of the Lumbar Spine Mimicking Malignancy on FDG PET/CT.

A 46-year-old man with over a 10-year history of gout complained of progressive bilateral buttock pain with numbness of legs for 4 months. Serum uric acid level was elevated. Lumbar radiographs showed decreased density of the bilateral L4-L5 facet joints. CT showed lytic lesions of the facet joints with hyperdense periarticular lesions. Enhanced MRI showed marked enhancement of these lesions. FDG PET/CT showed avid FDG uptake of the bony and periarticular lesions with SUVmax of 16.8. A decompressive posterior lumbar laminectomy with periarticular lesion resection was performed. Histopathologic findings of the periarticular lesions were consistent with tophaceous gout.