Incidental Detection of Glioblastoma Multiforme With PSMA Uptake on Initial Prostate Cancer Staging

We report the case of a 75-year-old man with prostate adenocarcinoma, referred for initial staging using 99mTc-PSMA scan. The whole body PSMA scan revealed a zone of increased uptake in the skull. Subsequent 99mTc-PSMA SPECT/CT imaging demonstrated a hypodense lesion in the brain parenchyma. Notably, the patient recently presented with left-sided hemiparesis. The subsequent MRI and surgical pathology confirmed the diagnosis of glioblastoma multiforme for the incidentally detected PSMA-avid lesion in the brain. This case highlights the importance of recognizing atypical PSMA-avid lesions to avoid misclassification as metastatic disease, thereby enhancing diagnostic accuracy. Furthermore, PSMA uptake in glioblastoma may serve as a potential target for theranostic approaches.