肾混合性上皮和间质肿瘤5例临床病理分析

Mixed epithelial and stromal tumor of the kidney:a clinicopathological analysis of five cases

目的探讨肾混合性上皮和间质肿瘤(mixed epithelial and stromal tumor of the kidney,MESTK)临床病理特征。方法收集5例MESTK的临床资料及随访结果,采用HE染色及免疫组织化学染色,观察组织学特征及免疫组织化学特点,并复习相关文献。结果5例均为女性,年龄44~62岁,平均51.2岁。临床表现主要为腰背部疼痛及血尿,影像学检查提示肾脏囊实性占位。病理大体表现为肾脏界线清楚的囊实性肿瘤,多位于肾中极;组织学特征:肿瘤由上皮和间质成分混合构成,上皮排列成小管、微囊、大囊、乳头等结构,间质由梭形细胞组成,疏密不一,可见卵巢样间质、间质水肿及慢性炎症细胞浸润,上皮及间质细胞均未见明显异型性。免疫组织化学:上皮细胞表达广谱细胞角蛋白(CK_(pan))、CK7、PAX-8、P504S,间质细胞大多表达结蛋白(desmin)、平滑肌肌动蛋白(SMA)、雌激素受体(ER)、孕激素受体(PR)、CD10,Ki-67增殖指数低。结论MESTK是一种罕见的良性肾脏肿瘤,好发于围绝经期女性,影像学检查常误诊为囊性肾癌,有独特的病理组织学和免疫组织化学表现,肿物完整切除后,预后良好。

Objective To investigate the clinicopathological features of mixed epithelial and stromal tumor of the kidney(MESTK).Methods Clinical data and follow-up result of 5 MESTK cases were collected.HE staining and immunohistochemical staining were used to observe the histological and immunohistochemical characteristics,and relevant literatures were reviewed.Results All the 5 cases were female,aged 44~62 years,with an average age of 51.2 years.The main clinical manifestations were low back pain and hematuria,and imaging examination showed a cystic and solid renal mass.The general pathological manifestations were cystic solid tumors with clear renal boundaries,mostly located in the middle pole of the kidney.Histological features showed that the tumor was composed of a mixture of epithelial and stroma components,with the epithelium arranged into tubules,microsacs,large sacs,papilla and other structures.The stroma was composed of spindle cells with different density.Ovarian-type stroma,interstitial edema and infiltration of chronic inflammatory cells were seen,and no obvious atypia was observed in the epithelial and stroma cells.Immunohistochemistry showed that epithelial cells expressed broad-spectrum cytokeratin(CKpan),CK7,PAX-8,and P504 S,while stroma cells mostly expressed desmin,smooth muscle actin(SMA),estrogen receptor(ER),progesterone receptor(PR),and CD10,with low Ki-67 proliferation index.Conclusion MESTK is a rare benign renal tumor,mostly occurring in perimenopausal women.It is often misdiagnosed as cystic renal carcinoma by imaging examination,with unique histopathological and immunohistochemical manifestations.After complete resection,the prognosis is good.