摘要目的:探讨肾脏血管平滑肌脂肪瘤伴上皮性囊肿（angiomyolipoma with epithelial cysts, AMLEC）的临床病理特征、诊断和鉴别诊断。方法:收集浙江省人民医院病理科2014年1月至2019年6月间诊断的4例肾脏AMLEC，观察其临床特征、形态学及免疫表型特点，并复习相关文献。结果:4例均为女性，年龄19~52岁（平均34.5岁）。3例为体检偶然发现，病史1~6年。术前影像学Bosniak分级：3例为Ⅲ级，1例为Ⅳ级。肿瘤最大径2.5~9.0 cm（平均5.0 cm）。镜下观察4例AMLEC均表现为3种组织学构成：（1）被覆单层立方/柱状、偶尔为鞋钉样上皮的单纯性囊肿；（2）紧邻囊肿上皮下为薄层的"生发层样"间质，由致密的富于细胞的苗勒样短梭形细胞组成，其内可见散在的慢性炎性细胞浸润；（3）最外层是厚的长束状的平滑肌样间质，常见围绕畸形的厚壁血管生长。肌束之间常见丰富的裂隙状淋巴管分割。4例肿瘤均无脂肪成分，瘤细胞形态温和，未见不典型性和核分裂象。免疫组织化学染色，囊肿被覆上皮强表达PAX8和CK7；上皮下"生发层样"间质强表达黑色素分化标志物（HMB45、Melan A、Cathspin K、MiTF）以及苗勒分化标志物（雌激素受体、孕激素受体、CD10），不表达平滑肌分化标志物（平滑肌肌动蛋白、结蛋白、calponin）；外层平滑肌样间质强表达平滑肌分化标志物，仅偶尔或散在表达黑色素分化标志物和苗勒分化标志物。3例术后获得随访信息，分别随访3、5及66个月均未见肿瘤复发或转移证据。结论:肾脏AMLEC是一种少见的血管平滑肌脂肪瘤组织学亚型，生物学行为良性，具有特征性的组织学和免疫表型特点。病理医师应熟悉AMLEC的临床病理表现谱，应将其包括在上皮和间叶双相特征肾肿瘤的鉴别诊断之中。

abstractsObjective:To investigate the clinicopathological features,diagnosis and differential diagnosis of renal angiomyolipoma with epithelial cysts(AMLEC).Methods:Four cases of renal AMLEC diagnosed between January 2014 and June 2019 at the Department of Pathology,Zhejiang Provincial People′s Hospital were subjected to clinicopathological, histological and immunohistochemistry analyses along with a literature review.Results:All the four patients were females and aged from 19 to 52 years (mean 34.5 years). Three cases were accidentally discovered by physical examination, and the medical history was 1 to 6 years. The preoperative imaging Bosniak classification was grade Ⅲ in 3 and grade Ⅳ in 1 case. The maximum diameter of the tumor ranged from 2.5 to 9.0 cm (average 5.0 cm). Histologically, all of the 4 tumors showed three histological components: (1) simple epithelial cysts lined by a layer of cuboidal/low-columnar to occasionally, hobnailcells; (2) a thin, compact subepithelial "cambium-like" layer of cellular, mullerian-like short spindle cell stromas with prominent admixedchronic inflammation; (3) a outermost layer of thick, long-fascicles of smooth muscle-like stromas, often surrounded by dysplastic, tortuous thick-walled blood vessels. There was often a prominent lymphatic channel network in the smooth muscle component forming slit like branched and curvilinear spaces. None of the 4 tumors had fat content.Immunohistochemically, the epithelial cells lining the cysts strongly expressed PAX8 and CK7. The subepithelial "cambium-like" stromas strongly expressed melanocytic markers (HMB45, Melan A, Cathspin K, MiTF) and mullerian markers (ER,PR,CD10), and were negative for smooth-muscle markers(SMA,desmin,calponin). The outermost layer of smooth muscle-like stromas strongly expressed smooth-muscle markers, and were only focally positive for melanocytic and mullerian markers. Follow-up information was obtained in 3 cases, among which no evidence of tumor recurrence or metastasis was found at 3, 5, and 66 months of follow-up, respectively.Conclusions:Renal AMLEC is a rare histological subtype of angiomyolipoma with benign biological behavior, and has characteristic histological and immunophenotypic characteristics.Pathologists should be familiar with the clinicopathological appearances of AMLEC and include it in the differential diagnostic spectrums of renal tumors with biphasic epithelial and mesenchymal features.