Shamsuddin A M, Phelps P C, Trump B F
Hum Pathol. 1982 Sep;13(9):790-803. doi: 10.1016/s0046-8177(82)80075-0.
Despite numerous reports of morphologic characteristics of premalignant and malignant large intestinal epithelium, the literature lacks comprehensive reports of the morphologic features of the epithelium of the normal large intestine, except of the rectum. Large intestinal epithelium from 41 persons was obtained, and samples from the ascending, transverse, descending, and rectosigmoid areas were studied by light microscopy, histochemical techniques, and transmission and scanning electron microscopy. The morphologic features and histochemical reactions of the various segments of the large intestine are different. Neutral mucopolysaccharide is predominant in the ascending colon, whereas the rectum has predominantly or exclusively acidic mucin. Only three basic epithelial cell phenotypes have been identified: undifferentiated cells, mucous cells, and endocrine cells. The columnar cells at the surface between the crypts appear to be a variant of mucous cells. Compared with other segments, the rectum shows an unusually high concentration of endocrine cells, positively correlating with the high incidence of carcinoid tumors in that segment of the large intestine. The mucous cells in all segments contain large mucous vacuoles and small apical vesicles. The apical vesicles show variable electron density, being most dense in the ascending colon and becoming progressively less dense at the transverse and descending colon and most electron-lucent in the sigmoid colon and rectum. Ultrastructurally, the mucin shows a variable degree of heterogeneity in the proximal segments. This study suggests that some of the previously described ultrastructural features of abnormal large-intestinal epithelium may be only the result of failure to compare the so-called abnormal cells with normal cells from the same region. Well-controlled studies of the abnormal epithelium of a particular segment of large intestine must include the normal epithelium from the identical segment as control in order to make interpretations accurate.
尽管有大量关于大肠癌前和恶性上皮形态学特征的报道，但除直肠外，文献中缺乏对正常大肠上皮形态学特征的全面报道。获取了41人的大肠上皮样本，并通过光学显微镜、组织化学技术以及透射和扫描电子显微镜对升结肠、横结肠、降结肠和直肠乙状结肠区域的样本进行了研究。大肠各段的形态学特征和组织化学反应各不相同。中性粘多糖在升结肠中占主导地位，而直肠中主要或仅含有酸性粘蛋白。仅鉴定出三种基本的上皮细胞表型：未分化细胞、粘液细胞和内分泌细胞。隐窝之间表面的柱状细胞似乎是粘液细胞的一种变体。与其他段相比，直肠显示出异常高浓度的内分泌细胞，这与该段大肠类癌肿瘤的高发病率呈正相关。所有段的粘液细胞都含有大的粘液泡和小的顶端小泡。顶端小泡显示出可变的电子密度，在升结肠中最致密，在横结肠和降结肠中逐渐变稀疏，在乙状结肠和直肠中电子密度最低。在超微结构上，近端段的粘蛋白显示出不同程度的异质性。这项研究表明，先前描述的大肠异常上皮的一些超微结构特征可能只是未能将所谓的异常细胞与来自同一区域的正常细胞进行比较的结果。为了使解释准确，对大肠特定段异常上皮的严格对照研究必须包括来自相同段的正常上皮作为对照。
