伴有横纹肌样特征的肾细胞癌7例临床病理分析

Renal cell carcinoma with rhabdoid features:a clinicopathologic study of 7 cases

目的：探讨具有横纹肌样特征的肾细胞癌（renal cell carcinoma,RCC）的临床病理特征及预后。方法：回顾1999~2009年间RCC 135例,其中具有横纹肌样特征的RCC 7例,光镜观察和免疫组织化学标记,并复习相关文献。结果：镜下肿瘤由经典的肾透明细胞癌区域和横纹肌样瘤区域组成,两者之间相互移行或有纤细的纤维组织分隔。横纹肌样特征的瘤细胞间缺乏黏附性或黏附性差;瘤细胞圆形或多边形,胞质丰富,嗜伊红色,细胞核偏位,空泡状,核仁明显,核旁胞质内可见红染、均质、透明的球形包涵体。免疫表型：横纹肌样特征的瘤细胞弥漫性表达vimentin（7/7）、panCK（7/7）、EMA（7/7）、CD10（7/7）;灶性弱表达NSE（3/7）、S-100蛋白（1/7）;desmin、myogenin、SMA、CK7、CK20、HMB45均阴性。核旁球形小体表达panCK、EMA、vimentin、CD10较具特征性。Ki-67在横纹肌样特征区表达明显高于经典型透明细胞癌区。CD34显示横纹肌样特征区血管较经典型透明细胞癌区明显减少。6例获得随访资料,随访3个月至8年,其中病死3例,转移1例,无瘤生存2例。结论：伴有横纹肌样特征的RCC是少见的具有较高侵袭性肿瘤,组织病理学、免疫表型和超微结构都与恶性横纹肌样瘤相似,可能为RCC新的亚型,预后较差。

Objective：To explore the clinicopathologic features and the prognosis of renal cell carcinoma（RCC） with rhabdoid features.Methods：It was reviewed a consecutive series of 135 RCCs during the period from 1999 to 2009.Seven（7/135,5.2%）cases of RCC with rhabdoid features were identified.After immunohistochemistry and optical microscopy were performed,relevant literatures were reviewed.Results：Histopathologically,the RCC of these cases included the regional components of the conventional clear cell RCC and the rhabdoid cells.There was transition or separation with fibrous capsule between rhabdoid cells and conventional RCCs.The rhabdoid regions characterized with lack of adhesion or poor adhesion.The rhabdoid cells were round or polygonal,and exhibited abundant eosinophilic cytoplasm,eccentric nuclei,vesicular chromatin pattern and prominent nucleoli.The hyaline eosinophilic globular inclusions also could be seen in paranuclear cytoplasm.The immunohistochemical study showed that vimentin（7/7）,panCK,（7/7）,EMA（7/7） and CD10（7/7） were expressed diffusely,and NSE（3/7）,S-100 protein（1/7） were expressed focally and weakly,while desmin,myogenin,SMA,CK7,CK20 and HMB45 were expressed negatively in the rhabdoid cells.A distinctive paranuclear spherical structures expressed panCK,EMA,vimentin and CD10 were observed characteristically.The expression of Ki-67 in rhabdoid region was higher than region of the conventional clear cell RCC.The expression of CD34 showed that compared with the conventional clear cell RCC region,vessels significantly reduced in the rhabdoid region.Among 7 cases,6 patients offered the information of follow-up（range from 3 to 96 months）,and 3 patients died from 3 months to 1.5 years after diagnosis,1 case was alive with known metastases,the other 2 patients were alive without clinically detectable carcinoma.Conclusions：The RCC with rhabdoid features is a rare neoplasm with highly aggressiveness.There were similar features of histopathology,immunophenotype and ultrastructur between the RCC with rhabdoid features and the RCC without rhabdoid features,and the fomer may be a new subtype of RCC with poor clinnical outcome.