18F-DCFPyL PET/CT in Oncocytoma.

A 76-year-old man with biochemical failure after primary radiotherapy for prostate cancer had no malignant disease detected on Tc-MDP bone scan and diagnostic CT. Prostate-specific membrane antigen (PSMA), a type II transmembrane glycoprotein, is overexpressed in prostate cancer cells. The PSMA-targeted F-DCFPyL PET/CT demonstrated lymph node disease and photopenic defects in the left kidney associated with a cyst and biopsy-proven oncocytoma. Prostate-specific membrane antigen is expressed in the neovasculature of several solid tumors. It has been reported that PSMA expression is seen in approximately 50% of oncocytoma versus 76% of clear cell renal carcinomas. Biopsy confirmation is needed regardless of F-DCFPyL avidity.