目的: 总结肾血管平滑肌脂肪瘤(renal angiomyolipoma, RAML)合并下腔静脉(inferior vena cava, IVC)瘤栓患者的临床特点，并探讨该类患者行肾部分切除术和瘤栓取出术的可行性。方法: 选取北京大学第三医院泌尿外科2014年4月至2023年3月诊断为RAML合并IVC瘤栓患者的病例资料进行回顾性分析，记录人口统计学和围手术期资料，包括年龄、性别、手术方式、随访时间等，并比较经典型血管平滑肌脂肪瘤(classical angiomyolipoma, CAML)合并IVC瘤栓患者与上皮样血管平滑肌脂肪瘤(epithelioid angiomyolipoma, EAML)合并IVC瘤栓患者的临床特点。结果: 共纳入11例患者，其中CAML合并IVC瘤栓患者7例，EAML合并IVC瘤栓患者4例。女性9例(9/11, 81.8%)，男性2例(2/11, 18.2%)，平均年龄(44.0±17.1)岁。9例患者(9/11, 81.8%)出现临床症状，包括腰痛、血尿、腹部包块等局部症状及体质量减轻、发热等系统性症状，2例(2/11, 18.2%)RAML合并IVC瘤栓患者没有出现临床症状，由体检发现。11例患者中10例行根治性肾切除术伴IVC瘤栓取出术，其中开腹手术3例(3/10, 30.0%)，腹腔镜手术2例(2/10, 20.0%)，机器人辅助腹腔镜手术5例(5/10, 50.0%)；另外1例患者行开放性肾部分切除术和瘤栓取出术。EAML合并IVC瘤栓的患者相较于CAML合并IVC瘤栓患者出现系统性临床症状(100% vs. 0%，P=0.003)的比例更高，术中出血量[400 (240, 3 050) mL vs. 50 (50, 300) mL，P =0.036]更多，并且出现肿瘤坏死(75% vs. 0%，P=0.024)的比例更高，但手术时间[(415.8±201.2) min vs. (226.0±87.3) min，P=0.053]两组间差异无统计学意义。结论: 与CAML伴IVC瘤栓患者相比，EAML伴IVC瘤栓患者出现系统性症状和肿瘤坏死的比例更高。此外，对于特定的CAML伴IVC瘤栓患者可以进行肾部分切除术和瘤栓取出术以更好地保留肾功能。

Objective: To summarize the clinical characteristics of patients with renal angiomyolipoma (RAML) combined with inferior vena cava (IVC) tumor thrombus, and to explore the feasibility of partial nephrectomy and thrombectomy in this series of patients. Methods: The clinical data of patients diagnosed with RAML combined with IVC tumor thrombus in the Department of Urology of the Peking University Third Hospital from April 2014 to March 2023 were retrospectively analyzed, and demographic and perioperative data of RAML patients with IVC tumor thrombus were recorded and collected from Electronic Medical Record System, including age, gender, surgical methods, and follow-up time, etc. The clinical characteristics between classic angiomyolipoma (CAML) patients with IVC tumor thrombus and epithelioid angiomyolipoma (EAML) patients with IVC tumor thrombus were compared to determine the clinical characteristics of these patients. Results: A total of 11 patients were included in this study, including 7 patients with CAML with IVC tumor thrombus and 4 patients with EAML with IVC tumor thrombus. There were 9 females (9/11, 81.8%) and 2 males (2/11, 18.2%), with an average age of (44.0±17.1) years. 9 patients (9/11, 81.8%) experienced clinical symptoms, including local symptoms including abdominal pain, hematuria, abdominal masses, and systemic symptoms including weight loss and fever; 2 patients (2/11, 18.2%) with RAML and IVC tumor thrombus did not show clinical symptoms, which were discovered by physical examination. Among the 11 patients, 10 underwent radical nephrectomy with thrombectomy, of whom, 3 underwent open surgery (3/10, 30.0%), 2 underwent laparoscopic surgery (2/10, 20.0%), and 5 underwent robot-assisted laparoscopic surgery (5/10, 50.0%). In addition, 1 patient underwent open partial nephrectomy and thrombectomy. The patients with EAML combined with IVC tumor thrombus had a higher proportion of systemic clinical symptoms (100% vs. 0%, P=0.003), more intraoperative bleeding [400 (240, 3 050) mL vs. 50 (50, 300) mL, P =0.036], and a higher proportion of tumor necrosis (75% vs. 0%, P=0.024) compared to the patients with CAML combined with IVC tumor thrombus. However, there was no statistically significant difference in operation time [(415.8±201.2) min vs. (226.0±87.3) min, P=0.053] between the two groups. Conclusion: Compared with the patients with CAML and IVC tumor thrombus, the patients with EAML and IVC tumor thrombus had a higher rate of systemic symptoms and tumor necrosis. In addition, in the selected patients with CAML with IVC tumor thrombus, partial nephrectomy and tumor thrombectomy could be performed to better preserve renal function.