Incidental prostate-specific membrane antigen-avid meningioma detected on 68Ga–prostate-specific membrane antigen PET/CT

Abstract

A 70-year-old gentleman with a history of Gleason score 7 (3 + 4) prostate adenocarcinoma was treated with radical prostatectomy with clear surgical margins. Postoperatively his prostate specific antigen was undetectable. However, his prostate specific antigen was slowly rising and he was referred for a 68 Galium-Prostate Specific Membrane Antigen (PSMA) PET/CT scan. Findings were suggestive of local prostatic cancer recurrence with no evidence of nodal or distant metastasis. An incidental PSMA avid focus was noted in the left frontal lobe, inseparable from the left frontal bone laterally. Subsequent MRI findings were consistent with meningioma. Meningioma is the most common primary brain tumor and may be a cause of false positive prostate cancer metastasis due to 68 Ga-PSMA uptake.

Prostate-specific membrane antigen expression in intracranial lesions — a review of the primary, metastatic, and nonneoplastic lesions

“…Usually, they are diagnosed after the 5 th decade of life and are often asymptomatic. In the literature, there have been accidental findings during the PET/CT examination with PSMA in the primary staging of PC [83] and in the diagnostic test for recurrence [84] and were also reported in the study by McLaughlin et al [45]. Similar findings with PSMA-positive meningiomas have been reported by other authors [85][86][87].…”