INTRODUCTION (continued)

If marginal excision has been performed and an examination is performed prior to subsequent wide excision, the goal of the radiologist is to adequately assist in surgical planning. It is not necessary or possible to attempt detection of minute foci of residual neoplasm but it is essential to detect any significant residual tumor.

Patient 1 20-year-old female with MR study obtained following marginal excision of parachordoma of leg. Click on image to view JPEG image.
1.	Axial T2W MR image reveals post surgical changes (arrow on JPEG image) and no mass. At surgery following wide excision minute microscopic residual tumor was identified. While MR imaging is unable to detect such microscopic foci, gross foci may be identifiable, thus aiding in surgical planning of wide excision.