Unsuspected Isolated Peritoneal Metastasis of Prostate Cancer Detected with Digital F-18 PSMA PET/CT Scan

We report the case of a prostate cancer (PC) patient referred to our center to perform F-18 prostate-specific membrane antigen (PSMA) digital positron emission tomography / computed tomography (PET/CT) scan for biochemical recurrence. PET/CT was unremarkable except for a tiny PSMA-expressing nodule on the right paracolic gutter, which increased in size and PSMA-expression on repeat imaging. Excision of the lesion was consistent with PC peritoneal metastasis. The isolated location of the lesion was atypical for PC metastasis. In the era of highly sensitive digital PET/CT detectors, it is always important to investigate abnormal uptake of F-18 PSMA regardless of the location.