18 F-PSMA PET/CT reveals occult pericardial inflammation.

18F-PSMA PET/CT is widely utilized for the detection and staging of prostate cancer due to its high affinity for prostate-specific membrane antigen (PSMA), which is overexpressed in malignant prostate tissue. PSMA ligands have also been shown to accumulate in non-prostatic tissues under certain pathological conditions, including inflammation. We report a case of inci dentally detected subclinical pericardial inflammation in a patient undergoing prostate cancer staging with 18F-PSMA PET/CT imaging. A 61-year-old male with histologically confir med, organ-confined prostate adenocarcinoma (Gleason score 7, Grade Group 2) underwent 18F-PSMA PET/CT clinically indicated for staging prior to radical prostatectomy. While no evidence of metastatic disease was found, the scan revealed mildly increased PSMA uptake along the pericardium with a small associated effusion. The patie nt had no clinical signs or symptoms of pericarditis, and comprehensive cardiac, infectious, and rheumatologic workup was unremarkable. Conservative management was pursued, and follow-up demonstrated resolution of the effusion with no clinical sequelae. Th is case illustrates that 18F-PSMA PET/CT, although performed for prostate cancer staging, may incidentally detect findings such as subclinical pericardial inflammation, emphasizing the importance of careful evaluation of extra-prostatic uptake. Further res earch is warranted to explore its potential role in identifying subclinical inflammatory conditions beyond oncology.