嗜酸性乳头状肾细胞癌6例临床病理分析

Clinicopathologic features of oncocytic papillary renal cell carcinoma

目的探讨嗜酸性乳头状肾细胞癌(OPRCC)的临床病理特点、免疫表型、遗传学改变及鉴别诊断。方法对6例OPRCC的临床资料、组织形态学、免疫组化及分子遗传学进行探讨,并复习文献。结果 OPRCC多发生于中老年人(平均年龄57岁),男女之比为5∶1。能够获得随访资料的4例患者均无瘤生存。所有病例的组织形态均以乳头状结构为主,乳头具有纤细的纤维血管轴心,乳头表面衬覆单层肿瘤细胞。瘤细胞胞质丰富、颗粒状、嗜酸性,胞核圆形或卵圆形;间质内常见泡沫巨噬细胞(4/6)及出血(5/6)。免疫组化:6例肿瘤细胞P504S、vimentin和CD10均弥漫强(+),部分病例E-cad、EMA和CK7(+),阳性率分别为83.3%(5/6)、33.3%(2/6)和16.7%(1/6);CD117均(-)。5例采用FISH方法检测7号、17号和Y染色体,其中3例存在7号染色体三倍体,2例存在17号染色体3倍体;4例男性患者中,1例存在Y染色体缺失。结论 OPRCC具有特殊的形态学特征和良好的临床预后,其免疫表型和分子遗传学改变与乳头状肾细胞癌高度相似。该肿瘤能否定义为乳头状肾细胞癌的特殊变异型尚待今后更大样本的研究。

Objective To study the clinicopathological features, immunophenotype, genetic changes and differential diagnosis of oncocytie papillary renal cell carcinoma （ OPRCC ）. Methods Six cases of OPRCC were investigated by elinicopathologic findings, immunohistoehemistry, and genetic analysis, and the related literature was also reviewed. Results OPRCC commonly occured in older patients （mean, 57 years） with a male predominant （male-to-female ratio was 5 ： 1 ）. Four patients with prognostic data were alive with no evidence of disease after initial resection. Histologically, tumors exhibited predominantly papillary structure with delicate fibrovascular cores. Papillae were lined by single layer of cells with large, deeply eosinophilic and finely granular cytoplasms and round regular nucleus. Most of our cases （4/6） showed foamy macrophages within papillary cores. Likewise, hemorrhages were observed in five of six cases. All tumors were immunoreactive for PS04s, vimentin, and CD10, and negative for CDl17. While E-eadherin, EMA, and cytokeratin 7 exhibited variable immunopositivity,the positive rates were 83%, 33%, and 17%, respectively. FISH analysis was performed in five of six cases and found heterogeneous results. Trisomy of chromosomes 7 was found in three cases and trisomy of chromosome 17 in two cases. Loss of chromosome Y was noted in one of four tumors in male patients. Conclusion OPRCC shows distinct morphology, indolent clinical behavior, and similar immunohistochemical and cytogenetic features with PRCC. Whether it exhibits a variant in the PRCC group is still unknown and requires further investigation in larger series.