Solitary 68Ga-PSMA-Avid Proximal Tibial Prostatic Adenocarcinoma Metastasis Mimicking Enthesopathy.

A 76-year-old man with previously treated prostatic adenocarcinoma (Gleason 8) was referred for a Ga-prostate-specific membrane antigen PET/CT scan due to a rising serum PSA level. An intensely PSMA-avid focus was demonstrated in the left proximal tibia with no evidence of local recurrence or metastatic disease elsewhere. This was diagnosed and managed as enthesopathy. A Tc-MDP bone scan with SPECT/CT performed 9 months later confirmed an intensely osteoblastic mixed lytic/sclerotic metastasis at the left proximal tibia.