Xiang Hua, Ding Wei, Liu Fang, Ren Guo-ping, Wang Zhao-ming, Zhu Xiong-zeng
Department of Pathology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
Zhonghua Bing Li Xue Za Zhi. 2009 Jul;38(7):436-40.
To study the clinicopathologic features, immunophenotype and differential diagnosis of mixed epithelial and stromal tumor of kidney (MEST) and adult cystic nephroma (CN).
Five cases of MEST and 4 cases of CN were retrospectively analyzed. Immunohistochemical study was carried out and the literature was reviewed.
All of the five patients with MEST were females. Their median age was 45 years. For CN, there were 3 males and 1 female and their median age was 41 years. All patients presented with loin pain and hematuria. On gross examination, MEST was well-circumscribed but non-encapsulated. There was no evidence of haemorrhage or necrosis. Three of the cases were solid in nature. One was composed of a mixture of solid and cystic elements, while the remaining case showed a multicystic cut surface bridged by thick fibrous septa. On the other hand, CN were well-circumscribed and encapsulated. They were multiloculated cystic in nature. The cystic spaces were separated by thin septa and there was no significant solid or necrotic component. Histologically, MEST consisted of proliferation of cystically dilated glands admixed with spindly stromal cells with various cellularity and growth patterns. Both the glandular and stromal elements were well-differentiated with no cytologic atypia identified. The glandular structures in 2 of the cases were partially lined by endometrial or tubal epithelium. In contrast, the thin-walled cystic spaces in CN were lined by a single layer of epithelium.Immunohistochemical study showed that the epithelial cells were positive for pan-cytokeratin and epithelial membrane antigen. The spindle cells in MEST expressed vimentin (5/5), smooth muscle actin (3/5), desmin (4/5), CD10 (5/5), estrogen receptor (4/5) and progesterone receptor (4/5). They were negative for HMB45, CD34, CD117 and S-100 protein. On the other hand, the spindle cells in CN were variably positive for vimentin (4/4), smooth muscle actin (4/4), desmin (1/4), estrogen receptor (3/4) and progesterone receptor (1/4). They were negative for CD10, HMB45, CD34, CD117 and S-100 protein.
Both MEST and CN are uncommon renal neoplasm. Most of them run a benign clinical course. The stromal cells in MEST show smooth muscle or myofibroblastic differentiation. Areas demonstrating Müllerian features also existed in some cases. MEST and CN share overlapping histological and immunohistochemical features, and may represent spectrum of the same group of lesions.
研究肾混合上皮和间质瘤（MEST）及成人囊性肾瘤（CN）的临床病理特征、免疫表型及鉴别诊断。
回顾性分析5例MEST和4例CN。进行免疫组织化学研究并复习相关文献。
5例MEST患者均为女性，中位年龄45岁。CN患者中，男性3例，女性1例，中位年龄41岁。所有患者均表现为腰痛和血尿。大体检查显示，MEST边界清晰但无包膜，无出血或坏死迹象。其中3例为实性，1例由实性和囊性成分混合组成，其余1例切面呈多囊性，有厚纤维间隔相连。另一方面，CN边界清晰且有包膜，本质上为多房囊性，囊腔由薄间隔分隔，无明显实性或坏死成分。组织学上，MEST由囊性扩张的腺体增生并伴有不同细胞密度和生长模式的梭形间质细胞组成。腺体和间质成分均分化良好，未发现细胞异型性。其中2例的腺管结构部分内衬子宫内膜或输卵管上皮。相比之下，CN的薄壁囊腔内衬单层上皮。免疫组织化学研究显示，上皮细胞对泛细胞角蛋白和上皮膜抗原呈阳性。MEST中的梭形细胞表达波形蛋白（5/5）、平滑肌肌动蛋白（3/5）、结蛋白（4/5）、CD10（5/5）、雌激素受体（4/5）和孕激素受体（4/5），对HMB45、CD34、CD117和S-100蛋白呈阴性。另一方面，CN中的梭形细胞对波形蛋白（4/4）、平滑肌肌动蛋白（4/4）、结蛋白（1/4）、雌激素受体（3/4）和孕激素受体（1/4）呈不同程度阳性，对CD10、HMB45、CD34、CD117和S-100蛋白呈阴性。
MEST和CN均为罕见的肾肿瘤，多数呈良性临床经过。MEST中的间质细胞显示平滑肌或肌成纤维细胞分化，部分病例还存在苗勒氏特征区域。MEST和CN在组织学和免疫组织化学特征上有重叠，可能代表同一组病变的不同表现。
