The Enneking classification of surgical margins is the only one which shows a reasonable correlation between the type of margin and the risk of local recurrence. However, it can be improved by a complementary definition of compartments and a better investigation of local tumor growth. Thus, if no open biopsy has been performed, a single muscle or a group of muscles, may constitute a compartment. Secondly, tumor growth at the border between the gross tumor and surrounding tissues should be better studied and classified. If preoperative radiotherapy is preferred, hopefully, growth patterns can be correlated with preoperative MR-findings to select patients who would benefit from radiotherapy combined with surgery. If postoperative radiotherapy is preferred, the operative specimen should be used for a microscopic classification of the tumor growth at the border, to make it possible to select only patients who need postoperative radiotherapy. Thus, it may be possible to combine Enneking's margins with a classification of tumor growth at the border, which permits a still better prognostication of local recurrence.