Dr. Thomas E. Shea: An 18-year-old girl was admitted because of pain in her thigh. She had been well until six months previously when she noted localized tenderness in the posterior aspect of her thigh. Two months before admission, she noted pain in the same area, which became more severe and persistent. Two weeks prior to admission she noted a mass in the thigh.
Physical examination revealed a 15-cm soft-tissue mass in the posterolateral aspect of the thigh, which was tender but not fluctuant.
Dr. Laurence L. Robbins: Dr. Hanelin, would you comment on this?Dr. Joseph Hanelin: There is a large soft-tissue mass and possibly some edema in the soft tissues (Fig 1), which indicates the presence of a deeply situated neoplasm or, less likely, an inflammatory process. There is no calcification within the tumor. There is a localized irregularity and destruction of a short segment of the