Heterogeneous 68Ga-Prostate-Specific Membrane Antigen Uptake in the Left Upper Abdomen: Mesenchymal Tumor

A 50-year-old man with recently diagnosed prostate adenocarcinoma was referred for whole-body Ga-prostate-specific membrane antigen (PSMA) PET/CT scan for staging. Apart from some nonspecific findings, Ga-PSMA PET/CT revealed large soft tissue mass in the left upper abdomen showing heterogeneous tracer uptake. Histological examination of the mass was interpreted as gastrointestinal/extragastrointestinal stromal tumor by pathologists. Prostate-specific membrane antigen is considered specific for prostate cancer cells, although PSMA activity has been described in many other benign or malign conditions. That is why PSMA uptake in uncommon locations for prostate cancer metastasis must be considered for second malignancies or other benign conditions.