伴横纹肌样特征的肾细胞癌的临床病理特征

目的探讨伴横纹肌样特征的肾细胞癌（RCC）的临床病理特征。方法对1995—2005年南京军区南京总医院常规外检档案352例RCC中的10例伴横纹肌样特征的RCC进行了光镜、免疫表型检测和超微结构观察,并结合临床病理特征进行分析。结果10例伴横纹肌样特征的RCC患者年龄33．69岁（平均年龄52岁）,男9例,女1例。5例肿瘤侵犯肾包膜,2例伴淋巴结转移,1例伴肺转移。组织学观察,10例伴横纹肌样特征的RCC中透明细胞型9例,乳头型1例,均可见不同程度的具横纹肌样特征的瘤细胞区域。横纹肌样特征的瘤细胞排列成梁索状、腺泡样、器官样或团片状,瘤细胞散在分布,细胞间无黏附或黏附性差,呈类圆形或多角形,核泡状、偏位,核仁突出,胞质内见红染均质包涵体样物,瘤组织常伴明显坏死。免疫组织化学观察,具横纹肌样特征的瘤细胞CD10、CK（AE1／AE3）、上皮细胞膜抗原（EMA）、波形蛋白均阳性表达,CK7、CK20、结蛋白、肌细胞生成素、α-平滑肌肌动蛋白（α-SMA）、肌肉特异性肌动蛋白（MSA）均阴性表达,神经元特异性烯醇化酶（NSE）、S-100蛋白灶性阳性表达。横纹肌样瘤细胞区Ki-67阳性表达较周围经典型瘤细胞区增高,两者比较差异有统计学意义（P〈0．05）。随访8例,2例于术后6个月及29个月死亡,6例存活。结论伴横纹肌样特征的RCC主要见于透明细胞型,应与胞质嗜酸的肾细胞肿瘤和肾恶性横纹肌样瘤等相鉴别。RCC中伴横纹肌样特征的瘤细胞较周围经典型瘤细胞Ki-67表达明显增高,可能与此类肿瘤临床生物学行为更具侵袭性有关。

Clinicopathologic study of renal cell carcinoma with rhabdoid features

OBJECTIVE: To study the clinicopathologic features and biologic behavior of renal cell carcinoma (RCC) with rhabdoid features. METHODS: Ten cases of RCC with rhabdoid features collected during the period from 1995 to 2005 were enrolled into the study. The clinical findings were analyzed and the hematoxylin and eosin-stained sections were reviewed. Immunohistochemistry and electron microscopy were also performed. RESULTS: The age of patients ranged from 33 to 69 years (mean age = 52 years). Nine of the patients were males and 1 female. Five patients showed evidence of perinephric invasion. Two patients presented with regional lymph node metastases and 1 patient showed distant metastasis to the lung. Histologically, the rhabdoid foci were characterized by loosely cohesive trabeculae, acini, lobules and clusters of rhabdoid cells in otherwise clear cell RCC (9 cases) or papillary RCC (1 case). The rhabdoid cells were round to polygonal in shape and contained globular eosinophilic inclusion bodies in the cytoplasm, eccentric nuclei, vesicular chromatin pattern and prominent nucleoli. Coagulative tumor necrosis was commonly seen. Immunohistochemical study showed that the rhabdoid cells were diffusely positive for CD10 (10/10), cytokeratin AE1/AE3 (10/10), epithelial membrane antigen (10/10) and vimentin (10/10). Focal staining for neuron-specific enolase and S-100 protein was also noted. They were negative for CK7, CK20 and myogenic markers (including myogenin, smooth muscle actin and muscle-specific actin). The mean Ki-67 labeling index of the rhabdoid component was higher than that of the non-rhabdoid component (P < 0.05). Follow-up information was available in 8 patients. While 6 patients are still alive without recurrence, 2 patients died of the disease 6 and 29 months respectively after the operation. CONCLUSIONS: RCC with rhabdoid elements are mainly observed in clear cell RCC and need to be distinguished from oncocytic renal tumors and malignant rhabdoid tumor of kidney. The higher proliferative activity in the rhabdoid areas may indicate more aggressive biologic behavior.