Scleroderma in Disguise: Symmetric Girdle-Muscle Uptake on 18F-DCFPyL PET/CT Revealing Inflammatory Myositis

Prostate-specific membrane antigen–targeted PET agents are mainly used for prostate cancer; however, uptake in non-prostatic inflammatory tissue can challenge the physician. We report the case of a 75-year-old man referred for characterization of an FDG-avid prostate focus with normal PSA. 18 F-DCFPyL PET/CT was performed. Incidental moderate symmetric uptake was found in the pelvic-girdle and paravertebral muscles, without morphologic correlate on CT. Elevated creatine kinase, a late scleroderma-pattern capillaroscopy, and muscle MRI confirmed scleroderma-associated myositis. This case emphasizes that symmetric muscular prostate-specific membrane antigen uptake can reveal active inflammatory myositis.