Giant retroperitoneal leiomyosarcoma of massive proportions: a case report.

Introduction: Retroperitoneal leiomyosarcoma is a rare malignant neoplasm with insidious growth and delayed clinical presentation. Giant tumors pose major surgical challenges because of their anatomical relationships and the frequent need for multivisceral resection to achieve oncological control. Case presentation: We report the case of a 47-year-old male who presented with progressive abdominal distension and nonspecific symptoms. Imaging revealed a massive retroperitoneal tumor occupying nearly the entire abdominal cavity, with marked displacement of adjacent structures. The patient underwent exploratory laparotomy, and a complete macroscopic resection was achieved without multivisceral resection. The tumor encased a long segment of the right ureter, requiring segmental ureteral resection and urinary diversion with nephrostomy. The specimen measured 55 × 31.6 × 18 cm and weighed 19.5 kg. Histopathology confirmed a grade II retroperitoneal leiomyosarcoma with tumor at the inked peripheral surgical margins, consistent with R1 resection. Early postoperative imaging showed no macroscopic residual disease. During follow-up, recurrent tumor burden was identified approximately 3 months after surgery. The patient continued ifosfamide-based chemotherapy and subsequently showed an estimated 60% reduction in tumor size, with preserved renal function. Discussion: This case illustrates that complete macroscopic resection with organ preservation may be feasible in selected patients with giant retroperitoneal leiomyosarcoma. However, this approach is patient-specific and does not replace multivisceral resection when required for oncological clearance. Conclusion: Tumor size alone should not preclude surgical intervention. Surgical strategy should be individualized according to tumor biology, anatomical relationships, resectability, and expected functional consequences.