A 20 year old man suffered severe right knee pain, especially when his right foot touched ground. The MRI findings suggested periosteal osteosarcoma, which led to a staging FDG PET/CT. The images showed not only a hypermetabolic right knee lesion but also focally elevated activity in select muscles, which was attributed to altered biomechanics. The resected lesion was pathologically proven as periosteal chondrosarcoma instead of periosteal osteosarcoma. In a follow-up period of 4 years after the surgery, there was no recurrent disease, nor any abnormality in the muscles which showed focal FDG activity on the initial FDG PET/CT.
From the *Department of Radiology, The Children’s Hospital of Philadelphia, Perelman School of Medicine University of Pennsylvania, Philadelphia, PA; and
†Department of Nuclear Medicine, Beijing Shijitan Hospital, Capital Medical University, Beijing, People's Republic of China.
Received for publication October 9, 2018; revision accepted October 14, 2018.
Conflicts of interest and sources of funding: none declared.
Correspondence to: Hongming Zhuang, MD, PhD, Department Radiology, The Children’s Hospital of Philadelphia, Perelman School of Medicine University of Pennsylvania, 34th and Civic Ctr Blvd, Philadelphia, PA 19104. E-mail: firstname.lastname@example.org.