Low-Grade Myofibroblastic Sarcoma Demonstrated on 99mTc-MDP Bone Scan and 18F-FDG PET/CT

A 24-year-old woman with left hip pain for 4 months was admitted. Radiographs of the left hip showed a radiolucent lesion in the proximal femur. The lesion demonstrated hypointensity on T1-weighted and high intensity on T2-weighted fat saturated images.Tc-99m-MDP bone scan and(18)F-FDG PET/CT illustrated intense radiotracer accumulation at the osteolytic lesion. Postoperative pathology confirmed a low-grade myofibroblastic sarcoma (LGMS). LGMS is a rare neoplasm, which often occurred in the head and neck region. Our case suggested that LGMS should be considered in the differential diagnosis of proximal femur lesion on(99m)Tc-MDP bone scan and(18)F-FDG PET/CT.