目的

腹膜后肾外及盆腔上皮样血管平滑肌脂肪瘤在临床上较为少见，部分呈恶性生物样改变。由于缺乏特异性的征状和影像学表现，患者常延误诊治。本研究通过总结既往病例的诊疗经验并行文献复习，旨在提高对该疾病的认识。

方法

回顾性整理并分析北京大学国际医院2014 年1 月～ 2024 年4 月共14 例行手术治疗且经病理确诊的腹膜后肾外及盆腔上皮样血管平滑肌脂肪瘤患者的临床资料，结合国内外文献对该疾病临床表现、影像学和病理学特征及诊疗进展进行总结。

结果

本组男性4 例，女性10 例。就诊时年龄20～67 岁，中位年龄39 岁。初发12 例（体检发现4 例，腹部不适5 例，腰痛2 例，排便障碍1 例），复发2 例。病灶位于腹膜后区域11 例，盆腔3 例。CT 平扫呈稍低或等密度，瘤体较大时内部可有出血、坏死等表现；增强扫描实性成分呈不均匀明显强化。本组所有患者均行开腹手术治疗。术后病理提示恶性10 例。免疫组化染色结果：HMB45 阳性85.7%（12/14），MelanA 阳性64.3%（9/14），SMA 阳性91.7%（11/12）。术后并发症2 例（腹腔出血1 例，伤口感染1 例），经保守治疗后好转。出院后规律随访，截至2024 年7 月，随访时间4～88 个月，中位时间35 个月。2 例失访，1 例（病例13）术后5 月复查CT 明确盆腔肿物复发（现口服西罗莫司治疗），1 例（病例5）腹主动脉壁残留肿物未见明显增大，余患者均未见肿瘤复发及转移。

结论

腹膜后肾外及盆腔上皮样血管平滑肌脂肪瘤好发于中青年女性，临床表现不典型，术前影像学检查诊断准确率低，易与脂肪肉瘤、血管源性肿瘤等混淆。确诊依赖术后病理及免疫组化，特异性同时表达黑色素标志物（HMB45、Melan-A）及肌源性标志物（SMA）是其特征。治疗方案首选手术切除，但mTOR 抑制剂的应用前景也较为客观。部分患者表现为恶性肿瘤学特征，可出现复发及远处转移，故术后需定期随访观察。

Objective

Retroperitoneal extrarenal or pelvic epithelioid angiomyolipomas are clinically rare, and some of them show malignant biological behavior.Due to the lack of specific symptoms and imaging findings, patients often experience a delayed diagnosis and treatment.This study aimed to improve the understanding of this disease by summarizing our diagnosis and treatment experience with 14 cases and reviewing the literature.

Methods

The clinical data of 14 patients with retroperitoneal extrarenal or pelvic epithelioid angiomyolipoma who underwent surgical treatment and achieved pathological confirmation in Peking University International Hospital from January 2014 to April 2024 were retrospectively analyzed.The clinical manifestations, imaging and pathological features, diagnosis, and treatment of the disease were summarized based on the domestic and foreign literature.

Results

There were 4 males and 10 females in this group.The patients ranged in age from 20 to 67 years at presentation, with a median age of 39 years.There were 12 cases of initial onset (4 cases discovered in physical examination, 5 cases of abdominal discomfort, 2 cases of low back pain, 1 case of constipation) and 2 cases of recurrence.The lesions were located in retroperitoneal region in 11 cases and pelvic cavity in 3 cases.Plain CT scans showed slightly lower or equal density, and the tumor could have internal bleeding and necrosis when it was large.The solid component showed uneven and obvious enhancement.All patients in this group underwent open surgery.Postoperative pathology indicated malignancy in 10 cases.Immunohistochemical staining was positive for HMB45 in 85.7% (12/14) of patients, for MelanA in 64.3% (9/14), and for SMA in 91.7%(11/12).Postoperative complications in 2 cases (abdominal hemorrhage in 1 case and wound infection in 1 case) improved after conservative treatment.The patients underwent regular follow-up after discharge.As of July 2024, the follow-up time ranged from 4～88 months, with a median time of 35 months.Two cases were lost to follow-up.One case (case 13) was confirmed to have pelvic tumor recurrence 5 months after surgery(being on oral sirolimus treatment now).One case (case 5) had no significant changes in residual tumor in abdominal aortic wall, and no tumor recurrence or metastasis was observed in the remaining patients.

Conclusion

Extraperitoneal extrarenal or pelvic epithelioid angiomyolipomas are most common in young and middle-aged women.The clinical manifestations of the disease are atypical.The low diagnostic accuracy of imaging examination easily leads to confusion with liposarcoma and vasogenic tumor.Diagnosis of the disease depends on postoperative pathology and immunohistochemistry.The specific simultaneous expression of melanin markers (HMB45 and Melan-A) and myogenic markers (SMA) is characteristic.Surgical resection is the preferred treatment option, but mTOR inhibitors are promising for the treatment of the disease.Some patients present with malignant neoplastic features.Tumor recurrence and distant metastasis can still occur in these patients even after surgical treatment, so regular follow-up observation is required after surgery.