Prostate-Specific Membrane Antigen in Low-Grade Fibromatosis
We report a case of fibromatosis demonstrating prostate-specific membrane antigen (PSMA)–positive scan. A 76-year-old man was under assessment because of rising prostate-specific antigen level. Bone scan showed abnormal soft tissue uptake of 99mTc-MDP adjacent to the right scapula, compatible with a mass in MRI, thereafter. Because of the unavailability of 68Ga-PSMA scan in our department and also high cost in other centers, the patient underwent 177Lu-PSMA for more assessment, which revealed PSMA-avid mass. Pathologic examination confirmed the diagnosis of low-grade fibromatosis. This report demonstrates another false-positive result of PSMA scan and highlights the importance of pathologic examination.