Incidental Intracranial Schwannoma With High 68 Ga-PSMA Uptake on PET/CT

A 67-year-old man with newly diagnosed prostate adenocarcinoma underwent 68 Ga-PSMA PET/CT for initial staging. In addition to intense focal uptake in the prostate gland consistent with the primary tumor, the scan demonstrated heterogeneous PSMA uptake in the inferior-anterior region of the left temporal lobe adjacent to the left cavernous sinus. Further evaluation of this intracranial lesion with brain MRI raised a differential diagnosis between prostate cancer metastasis and cavernous sinus meningioma. Ultimately, surgical resection and histopathologic analysis established the diagnosis of schwannoma.