Nucleolar organizer regions in human esophageal disorders: comparison with proliferating cell nuclear antigen by...

A silver colloid technique to demonstrate nucleolar organizer region-associated proteins (AgNORs) was performed on sections of 15 samples of human esophageal tissue, including five nonpathological esophageal epithelium, two esophageal dysplasia of the squamous epithelium, and eight esophageal squamous cell carcinomas. Initially we examined various protocols for AgNOR staining. Staining performed on 4% paraformaldehyde-fixed paraffin-embedded specimens with an incubation time of 30 min yielded the most satisfactory results. In nonpathological esophageal epithelium, the mean number of AgNOR counts per nucleus in the four layers of esophageal epithelium was greatest in the parabasal layer and was statistically significant. No significant differences were observed among the mean number of AgNOR counts per nucleus in the nonpathological parabasal layer, dysplasia, and carcinoma. Positive correlation was observed between the PCNA labeling index of esophageal disorders and the mean number of AgNOR particles per nucleus. Therefore, in esophageal disorders, the AgNOR staining per nucleus appears to correlate with proliferative activity but is of little practical value in discerning malignancy and/or aggressive biological behaviors.