The article discusses a case of a 67-year-old woman with a history of breast cancer who presented with back pain and was found to have a benign cartilaginous tumor in her spine. The use of 16α-[18F]Fluoro-17β-Estradiol (FES) PET/CT initially suggested bone metastasis, but further tests confirmed the benign nature of the tumor. The article highlights the importance of caution when interpreting FES-PET/CT results, as false-positive uptake can occur in benign cartilaginous lesions due to estrogen receptor expression.