Detected Huge Urinoma With 99mTc-PSMA Activity on Initial Prostate Cancer Staging

A 62-year-old man with newly diagnosed prostate adenocarcinoma underwent initial staging with 99mTc-PSMA and 99mTc-MDP whole-body scans. The bone scan revealed a small zone of tracer activity superior to the left kidney. Subsequent 99mTc-PSMA SPECT/CT revealed a fluid density collection in the left perinephric and pararenal space, extending from the left subdiaphragmatic area to the pelvic inlet. PSMA tracer activity was seen around the left kidney. Contrast-enhanced CT confirmed a perinephric fluid collection consistent with urinoma. This case underscores the importance of recognizing atypical patterns of 99mTc-PSMA uptake to improve diagnostic accuracy, avoid misinterpretation, and ensure appropriate patient management.