Surgery is the mainstay of treatment for localized soft-tissue sarcoma (STS). It consists primarily of resection of the tumor along with a cuff of surrounding healthy tissue. In limb and trunk wall sarcomas, this basically implies resection of the surrounding soft tissues, which are mainly muscles, subcutaneous fat, and skin. In the retroperitoneum, this necessarily should imply resection of adjacent viscera, even when they are not overtly involved. This is the only way to avoid/minimize the presence of tumor cells at the cut surface (ie, positive microscopic surgical margins). Positive microscopic surgical margins are associated with a higher risk of local failure, distant metastases, and death.[3-6] Moreover, for STS located at critical sites, such as retroperitoneal sarcoma (RPS), positive surgical margins may have a direct impact on survival, favoring the development of inoperable local recurrences. Indeed, unlike with STS arising in the extremities and trunk wall, local control in RPS poses a significant challenge and remains the leading cause of death, particularly in patients with low- to intermediate-grade tumors—roughly 75% of all cases.[8-13] Extending the resection to adjacent uninvolved viscera for primary RPS is the only way to minimize the presence of microscopic surgical margins and hence maximize the chance of cure. In essence, this strategy should often include ipsilateral nephrectomy and colectomy; locoregional peritonectomy and myomectomy (partial/total) of the muscle of the lateral/posterior abdominal wall (usually the psoas) (see Figure); splenectomy and left pancreatectomy, for tumors located on the left upper side; occasionally pancreaticoduodenectomy or hepatectomy, for tumors located on the right side; and vascular and bone resection only if vessels/bone are overtly infiltrated.