肾混合性上皮和间质肿瘤临床病理观察

Mixed epithelial and stromal tumor of the kidney:a clinicopathological study

目的探讨肾混合性上皮和间质肿瘤(mixed epithelial and stromal tumor of the kidney,MESTK)的临床病理特征和诊断要点。方法分析1例MESTK的临床病理资料,观察其组织学形态及免疫表型特征,并复习相关文献。结果患者,女性,61岁。肾占位术后标本病理检查结果示:肿瘤大体为多个囊腔和实性区域构成,镜下呈双向分化,主要由上皮和间质成分组成,两种成分相互交织存在,上皮由大囊、微囊和小管形成,囊壁被覆扁平、立方或高柱状上皮细胞,部分上皮具有苗勒细胞分化可能,间质呈粘液样改变。未见明显核分裂像和异形性。免疫组化表型:肿瘤上皮细胞表达CK、vimentin,肿瘤间质细胞表达desmin、ER、PR、SMA,而α-inhibin及CR表达阴性。结论MESTK是一种罕见的良性的混合性肿瘤,可能具有一定的恶性潜能,具有较为独特的上皮和间质的组织病理学特点(上皮成分是由大囊,微囊及小管组成,间质粘液样变性),应与肾脏其他囊性及双向分化的肿瘤相鉴别。

Objective To explore the clinicopathological features and diagnostic points of mixed epithelial and stromal tumors of the kidney(MESTK).Methods The clinical and pathological data of a case of MESTK were analyzed,histological morphology and immunophenotypic characteristics were observed,and related literatures were reviewed.Results A female patient,61 years old,was examined.Pathological examination of specimens after renal mass resection showed that the tumor was composed of multiple cystic and solid regions.The microscope view showed bidirectional differentiation and was mainly consisted of epithelial and interstitial components.The epithelial components and interstitial components were interwoven.The epithelium was formed by large cysts,microcapsules and small tubes.The wall was covered with flat,cubic,or tall columnar epithelial cells,and some of the epithelium showed the possibility of Mullerian cell differentiation.The stroma showed mucoid changes.There were no obvious mitotic figures and atypia in the epithelium and stroma.Immunohistochemical phenotype showed that tumor epithelial cells expressed CK and vimentin,and tumor stromal cells expressed desmin,ER,PR,and SMA,whileα-inhibin and CR showed negative expression.Conclusion MESTK is a rare,benign,mixed tumor that may have certain malignant potential.It has a unique histopathological feature of epithelium and stroma(The epithelium components were mainly composed of large cysts,microcapsules and small tubes and the stroma showed mucoid degeneration)and should be distinguished from other cystic and bidirectionally differentiated tumors in the kidney.