Presacral Benign Schwannoma Mimics Malignancy on 18F-FDG and 68Ga-FAPI PET/CT.

ABSTRACT We present findings of FDG PET/CT and FAPI PET/CT in a 55-year-old woman with a history of black stools and low-back pain. Pelvic CT detected a giant presacral mass that was suspected to be malignant. 18F-FDG and 68Ga-FAPI PET/CT showed that the mass had intense activity. Pathological examination confirmed the mass as a benign schwannoma.