The examination of the coloring mechanism of the human esophageal epithelium by Lugol's solution.

It has been well known that the normal esophageal epithelium is stained by a modified Lugol's solution. On the other hand, displastic or cancerous mucosa of the esophagus is not stained by Lugol's solution through the endoscopic staining method. It is not clear what kind of mechanism causes the coloring or uncoloring of these esophageal mucosa using Lugol's solution. Therefore, to clarify this mechanism, we examined the sections of surgically resected esophageal tissues with Lugol's solution using the light microscopy. At the same time, we detected an iodine element in each tissue instilled with Lugol's solution by means of X-ray microanalytic technique. In light microscopic study, the cells of the stratum corneum and stratum granulosa of the normal esophageal mucosa were strongly stained by Lugol's solution. Dysplastic epithelium showed a slight coloration property in its superficial layer. No cancerous lesions were histologically stained by Lugol's solution. In X-ray microanalytic study, the cells of stratum corneum and stratum granulosa displayed a high peak for iodine. An intermediate peak for iodine was detected in the superficial zone of the displastic mucosa. No peaks for iodine were found in any other portion of the cancer tissues. These results suggested that the difference in the coloration property of the normal esophageal epithelium, dysplastic regions and cancerous regions corresponded to the affinity of each of these cells of these regions with iodine.