腹膜后孤立性纤维肿瘤的临床分析：附7例报告

Clinical analysis of retroperitoneal solitary fibrous tumor: a report of 7 cases

摘要:

背景与目的 孤立性纤维肿瘤（SFT）是一种临床上较为少见的软组织肿瘤，既往文献报道SFT好发于胸膜，近年来研究表明其在全身多部位均可发生。由于SFT在腹膜后发生率低，故目前仍缺乏对腹膜后SFT的临床诊治的深入研究报道。因此。本文通过回顾7例腹膜后SFT患者资料，探讨该病的临床特点、诊治及预后，以期加强认识并引起重视。方法 回顾性分析西安交通大学第一附属医院2014年3月—2021年9月收治的7例手术或穿刺活检病理及免疫组化检查确诊为腹膜后SFT患者的临床及病理资料，总结分析患者的诊治及预后情况。结果 7例患者中，男4例，女3例；平均年龄（53.3±13.2）岁。临床表现缺乏特异性，1例无明显症状，其余6例因肿瘤压迫周围组织器官出现不同程度的症状，以腹胀、腹痛最为常见。术前5例患者行CTA检查，其中2例供血动脉来自髂内动脉分支，1例来自髂内动脉分支及腰动脉分支，1例来自肠系膜下动脉远端分支，1例来自脾动脉分支。6例患者行根治性手术切除，其中3例术前行介入栓塞术，3例行联合脏器切除。平均手术时间（372.5±91.3）min，平均出血量（1 200.0±1 031.5）mL，平均住院时间（25.7±9.3）d，术前栓塞患者与未栓塞患者术后平均住院时间分别为（10.3±4.2）d和（11.7±2.3）d，术后第1天平均引流量分别为（283.3±119.3）mL和（385.0±262.5）mL。未栓塞患者中术后出现肺部感染1例，腹膜后包裹性积液1例。肿瘤大小9 cm ×7 cm×6 cm~25 cm×20 cm×10 cm，镜下肿瘤细胞呈梭形，呈现不同程度异型性，疏密不均，偶可见薄壁“鹿角状”血管，间质常含有胶原纤维。免疫组化阳性率CD34、Ki-67均为100%（7/7），CD99、vimentin均为100%（6/6），STAT6为100%（5/5），Bcl-2为50%（3/6），S-100为14%（1/7）。随访2~66个月，失访1例，其余患者均未见复发或转移征象。结论 腹膜后SFT多无特异性临床表现，影像学检查对术前评估及制定手术方案具有指导意义，最终确诊依赖于病理检查及免疫组织化学结果。根治性手术切除是主要治疗手段，术前栓塞对缩短术后住院时间、减少术后引流量及并发症的发生具有积极作用，风险分层指导下术后长期随访具有重要意义。

Abstract:

Background and Aims Solitary fibrous tumor (SFT) is a rare subtype of soft tissue sarcoma in clinical practice. Previous studies reported that SFT occurs predominantly in the pleura, but recent studies demonstrated that it can also develop in many parts of the body. Because the occurrence rate of SFT in the retroperitoneal space is low, so there is still a lack of in-depth research on the clinical diagnosis and treatment of retroperitoneal SFT at present. Therefore, this study was performed to investigate the clinical features, diagnosis and treatment as well as the prognosis of retroperitoneal SFT through reviewing the data of 7 patients with this condition, so as to help facilitate further understanding and more attention.Methods The clinical and pathological data of 7 patients diagnosed with retroperitoneal SFT by pathological and immunohistochemical analysis after surgery or puncture biopsy in the First Affiliated Hospital of Xi'an Jiaotong University from March 2014 to September 2021 were retrospectively analyzed. The diagnosis, treatment and prognosis of the patients to summarized and analyzed.Results Among the 7 patients, 4 cases were males and 3 cases were females, with an average age of (53.3±13.2) years. The clinical symptoms were not specific, one of them had no obvious symptoms, while the other 6 cases showed varying degrees of symptoms due to tumor compression of the surrounding tissues and organs. The most common symptoms were bloating and abdominal pain. CTA examination was performed in 5 patients before operation. Among them, the tumor-feeding arteries arose from the branch of the internal iliac artery in two cases, from the internal iliac artery and the lumbar artery in one case, from the distal branch of the inferior mesenteric artery in one case, and from the splenic artery in one case, respectively. Six patients underwent radical surgical resection, of whom three cases underwent preoperative embolization and three cases underwent combined organ resection. The average operative time was (372.5±91.3) min, the average blood loss was (1 200.0±1 031.5) mL, and the average length of hospital stay was (25.7±9.3) d. For patients with and without preoperative embolization, the average length of hospital stay was (10.3±4.2) d and (11.7±2.3) d, the average drainage volume on the first postoperative day was (283.3±119.3) mL and (385.0±262.5) mL, respectively. Postoperative pulmonary infection and encapsulated retroperitoneal collections occurred in one case each among the patients without embolization. Tumor size ranged from 9 cm ×7 cm×6 cm to 25 cm×20 cm×10 cm. Microscopic examination of the tumor showed that there were spindle-shaped cells of uneven distribution with varying degrees of atypia, occasional findings of thin-walled "staghorn" vasculature, and frequent presence of collagen fibers in the interstitium. The positive rates of immunohistochemical staining for CD34 and Ki-67 were 100% (7/7), CD99 and vimentin were 100% (6/6), STAT6 was 100% (5/5), and Bcl-2 was 50% (3/6), and S-100 was 14% (1/7), respectively. During the follow-up period for 2-66 months, one case was lost to follow-up and no recurrence or metastasis was found in the other cases.Conclusion Retroperitoneal SFT has no specific clinical manifestations. Imaging examinations have guiding significance for preoperative evaluation and surgical planning, and the final diagnosis depends on the results of pathological examination and immunohistochemical analysis. Radical surgical resection is the main treatment method. Preoperative embolization has positive effect on shortening the postoperative hospital stay, reducing postoperative drainage volume and the occurrence of complications. Long-term follow-up guided by risk stratification is of great importance.