A 83 year-old man, with a history of PCa diagnosed 18 years before (pT4 pN0 pMx infiltrating the bladder, GS 6, ISUP grade 1, starting PSA serum values of 4.7 ng/ml), was performing routine follow-up with PSA serum values and [18F]F-choline PET/MR. The gene discussed is KLK3; the disease is posterior cortical atrophy.