術前血管栓塞輔助腹腔鏡切除大型後腹膜孤立性纖維瘤：罕見病例報告

沈毓明、黃勝賢

彰化基督教醫院泌尿外科

Preoperative Embolization Facilitating Laparoscopic Resection of a Large Hypervascular Retroperitoneal Solitary Fibrous Tumor: A Rare Case Report

Yu-Ming Shen, Sheng-Hsien Huang

Division of Urology, Department of Surgery, Changhua Christian Hospital

Introduction

Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm that rarely occurs in the retroperitoneum. Because of its deep location and indolent growth, patients usually present late with nonspecific symptoms. Surgical resection remains the cornerstone of treatment, yet large hypervascular tumors in the pelvis pose considerable intraoperative challenges. Minimally invasive resection of such lesions is seldom reported due to bleeding risk and complex anatomy. We describe a rare case of a large hypervascular retroperitoneal SFT managed with preoperative arterial embolization followed by laparoscopic excision. This combined approach minimized bleeding and enabled complete resection. The case highlights a multidisciplinary strategy integrating interventional radiology and minimally invasive surgery for complex pelvic SFTs.

Case presentation

A 68-year-old man with benign prostatic hyperplasia presented with a two-month history of progressive abdominal distension. CT and MRI revealed a 13-cm encapsulated left retroperitoneal mass compressing the bladder and ureter, causing hydronephrosis. Given its hypervascularity, preoperative bilateral internal iliac artery embolization was performed, followed by hand-assisted laparoscopic tumor excision. Dense adhesions to the bladder and ureter resulted in intraoperative bladder rupture, which was repaired primarily. Blood loss was 700 mL without transfusion. Pathology showed spindle cells in a patternless architecture with hemangiopericytoma-like vessels, positive for CD34 and STAT6, confirming solitary fibrous tumor. The tumor measured 14 cm with 40% necrosis, yielding an intermediate Demicco risk score. Postoperatively, bladder leakage and vesicoureteral reflux were managed conservatively. The patient remains under urologic follow-up with preserved renal function.

Discussion

Retroperitoneal SFTs are exceedingly rare and often remain silent until they grow large enough to compress adjacent organs. Imaging aids in detecting the mass but cannot definitively differentiate SFT from other spindle cell tumors. Histopathologic diagnosis is based on a “patternless” spindle cell proliferation with branching vessels and strong nuclear STAT6 expression due to NAB2–STAT6 fusion.

Complete resection is the mainstay of treatment, but the hypervascular nature and proximity to pelvic organs make surgery challenging. In our patient, preoperative transarterial embolization (TAE) effectively reduced vascularity, achieving intraoperative hemostasis and allowing safe laparoscopic resection—an approach seldom reported in the literature for retroperitoneal SFTs larger than 10 cm.

Compared with conventional open surgery, laparoscopic excision following embolization offers the benefits of minimal invasiveness, reduced blood loss, and faster recovery while maintaining oncologic safety. This demonstrates the feasibility of a staged, multidisciplinary approach combining interventional radiology and hand-assisted laparoscopic surgery for selected cases of hypervascular retroperitoneal SFTs.

Risk stratification using the Demicco model places our patient in the intermediate-risk group, with a roughly 10% five-year metastatic risk. Given the potential for late recurrence, long-term surveillance with imaging is recommended. This case emphasizes that, in patients with pelvic compression symptoms, rare retroperitoneal tumors such as SFT should be considered, and a planned multimodal surgical strategy may optimize outcomes.

Conclusion

Preoperative embolization followed by laparoscopic resection offers a safe and effective strategy for managing large hypervascular retroperitoneal SFTs. This approach minimizes intraoperative bleeding and facilitates complete excision. Awareness of atypical compressive abdominal symptoms and multidisciplinary planning are essential for accurate diagnosis and successful surgical management.

Figure 1. Large encapsulated left retroperitoneal mass compressing the bladder and ureter.