Gobbo Stefano, Eble John N, Maclennan Gregory T, Grignon David J, Shah Rajal B, Zhang Shaobo, Martignoni Guido, Brunelli Matteo, Cheng Liang
Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Am J Surg Pathol. 2008 Dec;32(12):1780-6. doi: 10.1097/PAS.0b013e31818649ed.
Although histologic features enable an accurate diagnosis in most renal carcinomas, overlapping morphologic findings between some renal neoplasms make subclassification difficult. Some renal carcinomas show papillary architecture but are composed extensively of cells with clear cytoplasm, and it is unclear whether they should be classified as clear cell renal cell carcinomas or papillary renal cell carcinomas. We analyzed the immunohistochemical profiles and the cytogenetic patterns of 14 renal carcinomas showing papillary architecture in which there were variable amounts of cells with clear cytoplasm. The patients were 8 women and 6 men (mean age: 54 y). Immunohistochemistry and fluorescence in situ hybridization analysis distinguished 2 different groups. The first consisted of 10 renal cell carcinomas with strong immunoreactivity for alpha-methyl coenzyme A racemase, of which 9 also expressed cytokeratin 7. All of these neoplasms showed gains of chromosome 7 or 17 and chromosome Y was lost in all the male patients whereas 3p deletion was detected only in one case. In the other 4 renal cell carcinomas, cytokeratin 7 was not detected and alpha-methylacyl-CoA racemase was positive in only 1. In these neoplasms, no gain of chromosome 7 or 17 and no loss of chromosome Y were observed, whereas 3p deletion was detected in 3 of them. None of the 14 neoplasms showed immunoreactivity for TFE3. The combined use of immunohistochemistry and cytogenetics enabled us to provide a definitive diagnosis for 12 of 14 renal cell carcinomas with papillary architecture and clear cell components: 9 cases were confirmed to be papillary renal cell carcinomas and 3 cases were confirmed to be clear cell renal cell carcinomas. Despite these ancillary techniques, 2 cases remained unclassified. Our study establishes the utility of these procedures in accurately classifying the great majority of renal cell carcinomas with these findings.
尽管组织学特征能在大多数肾癌中实现准确诊断，但部分肾肿瘤之间形态学表现重叠，使得亚分类困难。一些肾癌呈现乳头样结构，但广泛由胞质透明的细胞构成，它们应归类为透明细胞肾细胞癌还是乳头肾细胞癌尚不清楚。我们分析了14例呈现乳头样结构且含有不同数量胞质透明细胞的肾癌的免疫组化特征和细胞遗传学模式。患者包括8名女性和6名男性（平均年龄：54岁）。免疫组化和荧光原位杂交分析区分出2个不同组。第一组由10例对α-甲基辅酶A消旋酶有强免疫反应性的肾细胞癌组成，其中9例也表达细胞角蛋白7。所有这些肿瘤均显示7号或17号染色体增加，所有男性患者的Y染色体丢失，而仅1例检测到3p缺失。在另外4例肾细胞癌中，未检测到细胞角蛋白7，仅1例α-甲基酰基辅酶A消旋酶呈阳性。在这些肿瘤中，未观察到7号或17号染色体增加以及Y染色体丢失，而其中3例检测到3p缺失。14例肿瘤均未显示对TFE3的免疫反应性。免疫组化和细胞遗传学的联合应用使我们能够对14例具有乳头样结构和透明细胞成分的肾细胞癌中的12例做出明确诊断：9例被确认为乳头肾细胞癌，3例被确认为透明细胞肾细胞癌。尽管有这些辅助技术，仍有2例无法分类。我们的研究证实了这些方法在准确分类绝大多数具有这些表现的肾细胞癌中的实用性。
