Department of Pathology, The Johns Hopkins Hospital, Baltimore, MD 21231, USA.
Am J Surg Pathol. 2010 Sep;34(9):1344-50. doi: 10.1097/PAS.0b013e3181ec0810.
Clear cell change is seen in <1% of colonic tubular adenomas (TAs) and remains incompletely characterized. Associated adenocarcinomas can also demonstrate a clear cell phenotype. Eleven TAs with at least focal clear cell change with or without associated invasive adenocarcinoma, from 10 patients were studied. The lesions were stained with periodic acid-Schiff (PAS)/PAS-diastase and immunolabeled with antibodies to MUC2, MUC5AC, MUC6, CK7, CK20, and CDX2. Eight of 11 (77%) TAs with clear cell change had focal to extensive high-grade dysplasia. Two were associated with invasive clear cell adenocarcinoma. The adenomas and adenocarcinomas ranged from 0.5 to 3.5 cm. PAS/PAS-diastase stains showed minimal PAS(+) material in the clear cells. On immunohistochemical studies, the clear cells had decreased MUC2 labeling compared with the surrounding conventional adenoma in 9 of 11 (88%) cases, including the 2 clear cell adenocarcinomas. In 3 of the 11 lesions, the background TA showed at least focal MUC5 immunoreactivity, their associated clear cell area had decreased MUC5 labeling in all 3 cases. No immunoreactivity to MUC6 was observed in the background TAs and clear cells in all cases. Compared with background TA, both increased and decreased expression of CK7, CK20 (in quantity), and CDX2 (in intensity) were observed in the clear cells of TAs and adenocarcinomas. One of the clear cell adenocarcinomas was CK20, CK7, CDX2 and the other was CK20, CK7, CDX2-focal positive. Thus, although the clear cells have different MUC protein profiles than the background adenomatous epithelium, invasive clear cell adenocarcinomas retained the typical CK20(+)/CK7(-) profile of conventional adenocarcinomas. Our results indicate that clear cell adenocarcinomas can be primary to the colorectum with identifiable precursors. Awareness of them and their immunoprofile allows distinction from clear cell lesions from other sites.
在<1%的结肠管状腺瘤（TA）中可见到透明细胞改变，且其特征仍不完全明确。相关的腺癌也可能表现出透明细胞表型。研究了 10 例患者的 11 个至少有局灶性透明细胞改变的 TA，其中包括局灶性透明细胞改变伴或不伴相关浸润性腺癌。这些病变用过碘酸希夫（PAS）/PAS-二酶和针对 MUC2、MUC5AC、MUC6、CK7、CK20 和 CDX2 的抗体进行免疫标记。11 个透明细胞改变的 TA 中有 8 个（77%）有局灶性至广泛高级别异型增生。其中 2 个与浸润性透明细胞腺癌相关。这些腺瘤和腺癌的大小为 0.5 至 3.5 厘米。PAS/PAS-二酶染色显示透明细胞中仅有少量 PAS(+)物质。在免疫组织化学研究中，在 11 个病例中的 9 个（88%），包括 2 个透明细胞腺癌，透明细胞的 MUC2 标记较周围常规腺瘤减少。在 11 个病变中的 3 个中，背景 TA 至少有局灶性 MUC5 免疫反应性，其相关的透明细胞区域在所有 3 个病例中 MUC5 标记减少。在所有病例中，背景 TA 和透明细胞均无 MUC6 免疫反应性。与背景 TA 相比，在透明细胞的 TA 和腺癌中均观察到 CK7、CK20（数量）和 CDX2（强度）的表达增加和减少。1 个透明细胞腺癌为 CK20、CK7、CDX2 阳性，另 1 个为 CK20、CK7、CDX2 局灶阳性。因此，尽管透明细胞的 MUC 蛋白谱与背景腺瘤上皮不同，但浸润性透明细胞腺癌保留了常规腺癌的典型 CK20(+)/CK7(-)表型。我们的结果表明，透明细胞腺癌可以原发于结直肠，有可识别的前驱体。对它们及其免疫表型的认识有助于将其与来自其他部位的透明细胞病变区分开来。
