背景:由于肾细胞肿瘤的嗜酸性亚型具有重叠的组织形态学和免疫组织化学特征,因此鉴别诊断可能是一个挑战。我们的目的是调查罕见变种的肾细胞癌(RCC)的频率,如琥珀酸脱氢酶缺陷型RCC(SDDRCC),遗传性平滑肌瘤病和RCC(HLRCC)相关性RCC,嗜酸性粒细胞,固体,和我们人群中的囊性RCC(ESCRCC)。
方法:可考虑为嗜酸性细胞性肿瘤类别的肾肿瘤包括:91个具有嗜酸性细胞性细胞质的常规透明细胞RCCs,72个乳头状RCC,74个发色RCC,88个嗜酸细胞瘤,和其他37种罕见亚型。使用组织微阵列方法,琥珀酸脱氢酶B(SDHB),富马酸水合酶(FH),和细胞角蛋白20(CK20)抗体通过免疫组织化学进行。对于选定的病例,在整个块切片上重复免疫组织化学。还研究了这些抗体在鉴别诊断中的实用性。
结果:在三个肿瘤中检测到SDHB表达缺失,其中两个显示了SDDRCC的典型形态。在另外两个肿瘤中,SDHB显示弱的细胞质表达,没有线粒体模式(可能是SDHB缺陷)。没有一个肿瘤显示FH表达的丧失。用SDHB和FH抗体观察到异质反应。只有一个ESCRCC检测到弥漫性CK20阳性。
结论:SDDRCC,HLRCC相关的RCC,根据人群的不同,ESCRCC是非常罕见的肿瘤。应牢记SDHB和FH表达可能的弱染色和局灶性丧失,并且必须包括遗传测试以获得模棱两可的结果。
BACKGROUND: Differential diagnosis can be a challenge for eosinophilic subtypes of renal cell tumors due to their overlapping histomorphological and immunohistochemical features. We aimed to investigate the frequency of rare variants of renal cell carcinomas (RCCs) such as succinate dehydrogenase-deficient RCC (SDDRCC), hereditary leiomyomatosis and RCC (HLRCC)-associated RCC, and eosinophilic, solid, and cystic RCC (ESCRCC) in our population.
METHODS: Renal tumors which could be considered in the eosinophilic tumor category were included: 91 conventional clear cell RCCs with eosinophilic cytoplasm, 72 papillary RCCs, 74 chromophobe RCCs, 88 oncocytomas, and 37 other rare subtypes. Using the tissue microarray method, succinate dehydrogenase B (SDHB), fumarate hydratase (FH), and cytokeratin 20 (CK20) antibodies were performed by immunohistochemistry. Immunohistochemistry was repeated on whole block sections for selected cases. The utility of these antibodies in the differential diagnosis was also investigated.
RESULTS: Loss of SDHB expression was detected in three tumors, two of which showed typical morphology for SDDRCC. In additional two tumors, SDHB showed weak cytoplasmic expression without a mitochondrial pattern (possible-SDHB deficient). None of the tumors showed loss of FH expression. Heterogeneous reactions were observed with SDHB and FH antibodies. Only one ESCRCC was detected with diffuse CK20 positivity.
CONCLUSIONS: SDDRCCs, HLRCC-associated RCCs, and ESCRCCs are very rare tumors depending on the population. Possible weak staining and focal loss of SDHB and FH expression should be kept in mind and genetic testing must be included for equivocal results.