[Histochemical diagnosis of short segment Barrett's esophagus]

Recently, we have many chances of findings of Barrett's esophagus in routine endoscopic examination. It is also reported that we have few frequent findings of typical Barrett's esophagus, long segment Barrett's esophagus (LSBE) which is seen predominantly in Europe and United States, however the frequency of finding of short segment Barrett's esophagus (SSBE) and adenocarcinoma derived from SSBE is gradually increasing in Japan. So it is thought that precise diagnosis of SSBE and the evaluation of potential malignancy of SSBE are needed in the present medical management. The present study has shown the differences of characteristics of mucinous contents and malignant potentials between in SSBE and LSBE by use of biopsy specimen taken by endoscopic procedure. It is well known that Barrett's epithelium is categorized gastric fundic type, junctional type and specialized columnar epithelium, especially Barrett's mucosa is characterized by specialized columnar epithelium, e. g. incomplete epithelial type of intestinal metaplasia. We have set up two characteristic groups, gastric mucin dominant and intestinal mucin dominant by using specific mucin staining for MUC2, MUC5AC, Con A and CD10. In results, we confirmed that 80% of specialized columnar epithelia revealed intestinal mucin dominant in LSBE and 77% revealed gastric mucin dominant as compared with 23%, intestinal mucin dominant. Moreover, we have examined the ability of cell proliferation using Ki67-immunostaining in Barrett's epithelia. It was demonstrated that positive immunoactivity of Ki67 in proliferative zone was shown in 37.5% of gastric mucin dominant and 76.5% of intestinal mucin dominant. The results described above suggested that specialized columnar epithelia with intestinal mucin dominant have a higher potential of malignant transformation. We concluded that the evaluation of characteristics of mucinous contents in specialized columnar epithelia plays an important role in determination of high risk group of carcinogenesis in the case of SSBE.