Agawa S, Jass J R
Department of Pathology, University of Auckland School of Medicine, New Zealand.
J Clin Pathol. 1990 Jul;43(7):527-32. doi: 10.1136/jcp.43.7.527.
A change in sialic acid, notably loss of O acetyl substitution, was studied histochemically in a series of 93 colorectal adenomas that included 14 malignant polyps. Changes in sialic acid were uncommon in adenomas showing mild dysplasia but became increasingly common in moderately and severely dysplastic adenomas and were always present in carcinomatous areas. There was no correlation between a change in sialic acid and either size or villous architecture of benign adenomas. As mucin change often preceded the development of invasive cancer, it could not be used on its own to distinguish between epithelial displacement (pseudoinvasion) and malignant invasion. An abundant luminal accumulation of altered sialic acid in association with an epithelial lining that was non-mucin secreting, however, was specific for cancer. Conversely, the presence of unchanged intracellular or intraluminal O-acetyl sialic acid may help to exclude a diagnosis of malignancy in equivocal cases. The change is not specific for colorectal neoplasms and probably represents a metaplasia to a small intestinal phenotype.
在一系列93例大肠腺瘤（包括14例恶性息肉）中，对唾液酸的变化，尤其是O - 乙酰基取代的缺失进行了组织化学研究。唾液酸的变化在轻度发育异常的腺瘤中不常见，但在中度和重度发育异常的腺瘤中变得越来越常见，并且在癌区总是存在。唾液酸的变化与良性腺瘤的大小或绒毛结构之间没有相关性。由于粘蛋白变化通常先于浸润性癌的发生，因此它不能单独用于区分上皮移位（假浸润）和恶性浸润。然而，与非粘蛋白分泌的上皮衬里相关的大量改变的唾液酸腔内积聚是癌症特有的。相反，在可疑病例中，细胞内或腔内未改变的O - 乙酰基唾液酸的存在可能有助于排除恶性肿瘤的诊断。这种变化并非大肠肿瘤所特有，可能代表向小肠表型的化生。
