Olgac Semra, Hutchinson Brian, Tickoo Satish K, Reuter Victor E
Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Mod Pathol. 2006 Feb;19(2):218-24. doi: 10.1038/modpathol.3800520.
Metanephric adenoma (MA), a well-described renal neoplasm, usually behaves in a benign fashion. It may have areas that are morphologically similar to papillary renal cell carcinoma (RCC) type, or epithelial (tubular predominant) type Wilms' tumor. Prior immunohistochemical studies of MA have reported variable staining patterns. Alpha-methylacyl-CoA racemase (AMACR), a molecular marker for prostate carcinoma, has subsequently been found to be overexpressed in breast, colorectal and ovarian cancers, among others. Recent microarray analysis of renal tumors has shown an increase of AMACR mRNA levels in papillary RCC but not in other subtypes. We investigated the utility of immunohistochemical staining for AMACR, cytokeratin 7(CK7), CD57 and WT1 to differentiate between the above-mentioned three neoplasms. Immunohistochemical stains were performed on paraffin-embedded tissue sections from 25 papillary RCC, 10 MAs and eight Wilms' tumors. AMACR was positive in one (10%) of 10 MAs and 24 (96%) of 25 papillary RCC, while it was negative in all Wilms' tumors. CK7 was positive in 20 of 25 papillary RCCs, focally positive in one Wilms' tumor and was negative in all MAs. CD57 was positive in all six MAs that were stained, focally positive in one of 25 papillary RCC and one of eight Wilms' tumors. WT1 was positive in seven of 10 MAs, three of 25 papillary RCCs and all eight Wilms' tumors. In conclusion, diffuse and strong immunoreactivity for AMACR may be useful in differentiating papillary RCC from MA but a panel which includes AMACR, CK7 and CD57 is better in this differential diagnosis. AMACR is not helpful in differentiating MA from Wilms' tumor, but CD57 is helpful in this differential diagnosis. WT1 may be useful in separating Wilms' tumor from MA and papillary RCC but is not helpful in differentiating MA from papillary RCC.
后肾腺瘤（MA）是一种已被充分描述的肾肿瘤，通常表现为良性。它可能有形态上类似于乳头状肾细胞癌（RCC）类型或上皮（以管状为主）型威尔姆斯瘤的区域。先前对MA的免疫组织化学研究报告了不同的染色模式。α-甲基酰基辅酶A消旋酶（AMACR）是前列腺癌的一种分子标志物，随后发现在乳腺癌、结直肠癌和卵巢癌等中过表达。最近对肾肿瘤的微阵列分析显示，乳头状RCC中AMACR mRNA水平升高，而其他亚型中未升高。我们研究了AMACR、细胞角蛋白7（CK7）、CD57和WT1免疫组织化学染色在鉴别上述三种肿瘤中的应用。对25例乳头状RCC、10例MA和8例威尔姆斯瘤的石蜡包埋组织切片进行免疫组织化学染色。AMACR在10例MA中的1例（10%）和25例乳头状RCC中的24例（96%）呈阳性，而在所有威尔姆斯瘤中均为阴性。CK7在25例乳头状RCC中的20例呈阳性，在1例威尔姆斯瘤中局灶性阳性，在所有MA中均为阴性。CD57在所有6例染色的MA中呈阳性，在25例乳头状RCC中的1例和8例威尔姆斯瘤中的1例局灶性阳性。WT1在10例MA中的7例、25例乳头状RCC中的3例和所有8例威尔姆斯瘤中呈阳性。总之，AMACR的弥漫性和强免疫反应性可能有助于将乳头状RCC与MA区分开来，但包括AMACR、CK7和CD57的一组指标在这种鉴别诊断中更好。AMACR对鉴别MA与威尔姆斯瘤无帮助，但CD57在这种鉴别诊断中有帮助。WT1可能有助于将威尔姆斯瘤与MA和乳头状RCC区分开来，但对鉴别MA与乳头状RCC无帮助。
