Elevated prostate-specific antigen in Paget's disease.

A 70-year-old man diagnosed with acinar adenocarcinoma prostate (Gleason score 4 + 4 = 8) underwent bone scintigraphy due to high serum prostate-specific antigen level (224 ng/mL; normal <4 ng/mL). Bone scan revealed moderately increased diffuse tracer uptake in the right hemipelvis, while the rest of the scan appeared normal, leading to suspicion of Paget's disease. Gallium-68-prostate-specific membrane antigen (PSMA) positron emission tomography-computed tomography scan (CT) showed a PSMA-avid lesion in the left lobe of the prostate, with no PSMA uptake in the areas of diffuse sclerosis in the right hemipelvis, as seen on CT. This confirmed the diagnosis of Paget's disease.