A 74 year-old man with a new diagnosis of PCa (Gleason Score—GS—equal to 9, 4 + 5; ISUP grade: 4) and a serum PSA value of 2.82 ng/ml, underwent [18F]F-choline PET/CT for the initial staging of disease. The gene discussed is KLK3; the disease is posterior cortical atrophy.