肾混合性上皮间质肿瘤和成人囊性肾瘤的临床病理学观察

目的 探讨肾混合性上皮间质肿瘤(MEST)和成人囊性肾瘤的临床病理学特点、免疫表型和鉴别诊断.方法 通过HE和免疫组织化学染色(EnVision法)分析5例MEST和4例囊性肾瘤,并复习有关文献.结果 5例MEST均为女性,中位年龄45岁;囊性肾瘤中男性3例,女性1例,中位年龄41岁;临床表现为腰痛或血尿.大体观察:MEST界清无包膜,切面未见明显出血坏死,其中3例旱实性,1例呈囊实性,另1例呈多囊性其间为厚的纤维分隔;囊性肾瘤有包膜,切面呈多囊性,囊壁薄,无实区和坏死厌.镜下观察:MEST由不等量增生、囊性扩张的腺上皮与不同排列方式的梭形间质细胞混合组成,两种细胞成分无明显异形,2例局部衬覆子宫内膜样或输卵管样上皮;囊性肾瘤为多房囊腔组织,囊壁薄,内衬单层上皮.免疫表型:9例上皮细胞CKpan、上皮细胞膜抗原(EMA)均呈阳性表达;MEST间质梭形细胞波形蛋白(5/5)、平滑肌肌动蛋白(SMA,3/5)、结蛋白(4/5)、CD10(5/5)、ER(4/5)和PR(4/5)呈阳性表达,HMB45、CD34、CD117和S-100蛋白呈阴性;囊性肾瘤间质成分波形蛋白(4/4)、SMA(4/4)、结蛋白(1/4)阳性,ER(3/4)和PR(1/4)少量细胞阳性,CDIO、HMB45、CD34、CDll7和S-100蛋白呈阴性.结论 (1)MEST和囊性肾瘤均是少见的肾脏肿瘤,大多为良性.(2)MEST间叶细胞呈不同程度的平滑肌或肌纤维母细胞分化;2例有MaUerian管上皮分化特征.(3)MEST和成人囊性肾瘤在形态学和免疫表型上有很多相似性,可能为位于同一肿瘤谱系两端的肿瘤.

Clinicopathologic annlysis of mixed epithelial and stromal tumor of kidney and adult cystic nephroma

Objective To study the clinicopathologie features,immunophenotype and differential diagnosis of mixed epithelial and stromal tumor of kidney ( MEST) and adult cystic nephroma ( CN).Methods Five cases of MEST and 4 cases of CN were retrospectively analyzed.Immunohistochemical study was carried out and the literature was reviewed.Results 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.Conclusions 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 Miillerian 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.