Abstract：
a-Methylacyl coenzyme A racemase (AMACR) is traditionally considered to be a marker of papillary renal cell carcinoma. However, AMACR expression can be seen in other renal tumors. The aim of this study was to investigate AMACR immunoreactivity within the spectrum of clear cell renal cell neoplasms. Fifty-three clear cell renal epithelial tumors were used in assembling the following four cohorts: low grade (LG) clear cell renal cell carcinoma (CCRCC), high grade (HG) CCRCC, CCRCC with cystic changes, and multilocular cystic renal neoplasm of low malignant potential (MCRNLMP). Representative blocks were stained for AMACR, using two different clones (SP52 and OV-TL12/30). There were at least some AMACR immunoreactivity in 77.8 % and 68.9 % of CCRCCs (using SP52 and OV-TL12/30 clone, respectively). Moderate to strong positivity, or positivity in more than one third of the tumor (even weak in intensity) was detected in 46.7 % of CCRCCs using SP52 and in 48.9 % of CCRCC using OV-TL12/30 clone. The highest AMACR reactivity was observed in HG CCRCC (60 % by SP52 and 66.7 % by OV-TL12/30). Strong and diffuse AMACR positivity was detected in 8.9 % of all CCRCCs. AMACR immunoreactivity in MCRNLMP was 37.5 % (SP52 clone) and 25 % (OV-TL12/30 clone). We demonstrated relatively high expression rate of AMACR in CCRCC, while very variable in intensity and distribution. This finding may have diagnostic implications especially in limited samples (i.e., core biopsies), as AMACR positivity does not exclude the diagnosis of CCRCC.
摘要：
α-甲酰基辅酶A消旋酶(AMACR)传统上被认为是乳头状肾细胞癌的标志物。然而,在其他肾肿瘤中可见AMACR表达。这项研究的目的是研究透明细胞肾细胞肿瘤范围内的AMACR免疫反应性。53个透明细胞肾上皮肿瘤用于组装以下四个队列：低级别（LG）透明细胞肾细胞癌（CCRCC），高品位（HG）CCRCC，CCRCC伴囊性改变，和低恶性潜能的多房性囊性肾肿瘤（MCRNLMP）。代表性块对AMACR染色,使用两个不同的克隆（SP52和OV-TL12/30）。在77.8％和68.9％的CCRCC中至少有一些AMACR免疫反应性（使用SP52和OV-TL12/30克隆，分别)。中等到强烈的积极性，使用SP52在46.7％的CCRCC和使用OV-TL12/30克隆在48.9％的CCRCC中检测到超过三分之一的肿瘤（甚至强度较弱）的阳性。在HGCCRCC中观察到最高的AMACR反应性（SP52为60％，OV-TL12/30为66.7％）。在所有CCRCC的8.9％中检测到强烈和弥漫性AMACR阳性。MCRNLMP中的AMACR免疫反应性为37.5%(SP52克隆)和25%(OV-TL12/30克隆)。我们证明AMACR在CCRCC中的表达率相对较高，而强度和分布变化很大。这一发现可能具有诊断意义，特别是在有限的样本中(即，核心活检)，因为AMACR阳性并不排除CCRCC的诊断。
