A team from Cleveland, Ohio, USA, prospectively evaluated the methylene blue staining properties of dysplastic and nondysplastic Barrett's esophagus. They also investigated the association of these properties with the risk for dysplasia and cancer.
In an ex vivo study, the researchers mapped, photographed, and sampled esophagectomy specimens with high-grade dysplasia and/or early adenocarcinoma, before and after methylene-blue staining.
In a concurrent in vivo study, methylene-blue staining and characterized methylene-blue stain characteristics were examined.
Pathologists estimated the proportion of specialized columnar epithelium in each specimen and graded dysplasia.
A total of 551 biopsies from 47 patients with biopsy-proven Barrett's esophagus, and 48 sections from 5 surgical specimens with Barrett's esophagus and dysplasia and early adenocarcinoma were analyzed.
The accuracy of ex vivo and in vivo methylene blue staining for specialized columnar epithelium was found to be 87% and 90%, respectively.
|Predictors of high-grade dysplasia and cancer:|
- Increased heterogeneity of staining
- Decreased intensity of staining
The length of Barrett's esophagus, biopsy location, and the presence of esophagitis and/or dysplasia influenced the staining.
Light-to-absent staining and moderate-to-marked heterogeneity were significantly associated with high-grade dysplasia or cancer in the univariate analysis. This was also true in a multivariate model that adjusted for the length of Barrett's esophagus and the presence of a lesion.
These staining characteristics were present in all patients with severe dysplasia and/or adenocarcinoma.
M. I. F. Canto, of the Case Western Reserve University, concluded on behalf of the group, "Highly dysplastic or malignant Barrett's esophagus stains differently with methylene blue.
"Increased heterogeneity and decreased methylene-blue stain intensity are significant independent predictors of high-grade dysplasia and/or cancer. These features may help to direct biopsies in patients without a lesion."