Mac Mylinh T, Chung Fai, Lin Fan, Hui Pei, Balzer Bonnie L, Wang Hanlin L
Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
Am J Clin Pathol. 2009 Jul;132(1):80-5. doi: 10.1309/AJCPUD0P5NQBOYPK.
Hepatocyte antigen is recognized by antibody Hep Par 1, a widely used diagnostic immunomarker for hepatocellular carcinoma and tumors with hepatoid differentiation. Hepatocyte antigen expression has also been detected in nonneoplastic small intestinal epithelium, but expression in small intestinal adenocarcinoma has not been well investigated. We immunohistochemically examined 39 nonampullary small intestinal adenocarcinomas for hepatocyte antigen expression; 34 cases contained normal-appearing nonneoplastic small intestinal mucosa on the same tissue sections. In 30 cases (88%), the nonneoplastic mucosa exhibited granular cytoplasmic Hep Par 1 staining exclusively in the epithelium. Only 9 small intestinal adenocarcinomas (23%) showed focal positive cytoplasmic staining. Nonneoplastic colonic epithelium was negative for Hep Par 1. In 31 colorectal adenocarcinomas, 3 (10%) showed positive staining for Hep Par 1 (1 diffuse, 2 focal), a frequency not different from that for small intestinal adenocarcinomas (P = .2467). Tumors expressing hepatocyte antigen did not exhibit evidence of hepatoid differentiation and were histologically indistinguishable from hepatocyte antigen-negative tumors. Hepatocyte antigen immunoreactivity is selectively expressed in nonneoplastic small intestinal enterocytes but not in colonocytes, suggesting a potential physiologic role in intestinal biology. Whether the loss of antigen expression in a large number of small intestinal adenocarcinomas serves a role in small intestinal tumorigenesis remains to be investigated.
肝细胞抗原可被抗体Hep Par 1识别，Hep Par 1是一种广泛用于肝细胞癌及具有肝样分化肿瘤的诊断性免疫标志物。在非肿瘤性小肠上皮中也检测到了肝细胞抗原表达，但小肠腺癌中的表达情况尚未得到充分研究。我们采用免疫组化方法检测了39例非壶腹型小肠腺癌的肝细胞抗原表达情况；34例病例的同一组织切片中含有外观正常的非肿瘤性小肠黏膜。在30例（88%）病例中，非肿瘤性黏膜仅在上皮细胞中呈现颗粒状细胞质Hep Par 1染色。仅有9例小肠腺癌（23%）显示局灶性细胞质阳性染色。非肿瘤性结肠上皮Hep Par 1呈阴性。在31例结直肠癌中，3例（10%）显示Hep Par 1阳性染色（1例弥漫性、2例局灶性），其频率与小肠腺癌无差异（P = 0.2467）。表达肝细胞抗原的肿瘤未表现出肝样分化的证据，在组织学上与肝细胞抗原阴性的肿瘤无法区分。肝细胞抗原免疫反应性在非肿瘤性小肠肠上皮细胞中选择性表达，而在结肠上皮细胞中不表达，提示其在肠道生物学中可能具有潜在的生理作用。大量小肠腺癌中抗原表达的缺失是否在小肠肿瘤发生中起作用仍有待研究。
