Should Special Staining (AB/PAS) be Routinely Performed in Gastric Biopsies for the Detection of Intestinal Metaplasia?

Background. Gastric intestinal metaplasia increases the risk of gastric cancer by nine times. Although attempts are made to diagnose it using endoscopic methods, the final diagnosis is established by examining and reporting biopsy samples. Although there are studies in the literature that do not recommend routine special staining, many laboratories routinely perform alcian blue/periodic acid Schiffs (AB/PAS) staining, in addition to hematoxylin and eosin (H&E) staining. In this study, we examined the need for performing routine special staining. Methods. Seven hundred forty-one consecutive gastric biopsies obtained from the archive of our laboratory in 2019 were included in the study. One day after evaluating the cases using H&E, they were evaluated with AB/PAS without examining the H&E results. Result. All of the intestinal metaplasia lesions detected in H&E were observed with AB/PAS. However, we missed 14 (13.73%) of 102 intestinal metaplasia lesions with H&E that we detected using AB/PAS. We found the sensitivity and specificity of H&E in detecting intestinal metaplasia were 86.3% and 99.7%, respectively. When we retrospectively examined the 14 missed lesions in H&E staining, we could observe intestinal metaplasia in six biopsies, but it was not possible in eight (7.8%). Conclusion. Considering that gastric intestinal metaplasia is a precancerous lesion, we think that this ratio (13.73%) is high and that the number of malignancies can be reduced with a low-cost special stain. In this context, we advocate and recommend routinely performing inexpensive special staining such as AB/PAS to detect intestinal metaplasia in all gastric biopsies.