[Morphology, immunohistochemistry and hTERC gene in-situ hybridization in Barrett's esophagus].

Objective: To study the clinicopathologic features and differential diagnosis of proximal gastric mucosa and mucosa of Barrett's esophagus (BE) in biopsy specimens.

Method: Thirty-eight cases of Barrett's esophagus (diagnosed using WHO criteria) and 44 cases of proximal gastric mucosa were studied by immunohistochemistry (for CK7, CK20, CK4, CK8, S-100 protein, MUC6, COX2 and bcl-2) and fluorescence in-situ hybridization (FISH) (for hTERC gene). The pathologic features were analyzed.

Results: The differences in expression of CK7, CK20, MUC6, COX2 and bcl-2 between BE and proximal gastric mucosa with intestinal metaplasia were not statistically significant (P > 0.05). There was however a statistically significant difference in expression of S-100 protein (P < 0.05). The expression of CK7/CK4 and CK7/CK8 in BE showed positive correlation (P < 0.05). However, such correlation was not demonstrated in proximal gastric mucosa (P > 0.05). The results of hTERC gene expression by FISH showed a statistically significant difference between the two groups: 57.9% (22/38) in BE and 13.6% (6/44) in proximal gastric mucosa (P < 0.05).

Conclusions: The significance of CK7 and CK20 expression is uncertain in the differential diagnosis between BE and proximal gastric mucosa. On the other hand, positivity for CK7/CK4/CK8 may support the diagnosis of BE and play a role in distinguishing between the two groups. S-100 protein expression and detection of hTERC gene amplification also contribute to the diagnosis of BE.