Examination of the characteristics of esophageal superficial cancer that could not be recognized without iodine spraying

Some early esophageal carcinomas are not visible on white light observation (WLI) or narrow-band imaging (NBI) and identified by iodine staining. Of the 39 cases and 55 lesions of early esophageal carcinomas discovered at our hospital between January 2021 and January 2024, only two lesions (3.6%) were not visible by WLI/NBI and identified by iodine staining. The two lesions that could only be recognized by iodine spraying were small against the esophageal background of iodine-free grade C in a man with a history of drinking and smoking who had been treated for head and neck and esophageal cancers. Early esophageal carcinoma is often recognized by WLI/NBI, but there are lesions that cannot be recognized without iodine spraying; therefore, the anterior wall in the tangential direction should be observed. If there is a history of treatment for head and neck and esophageal cancers or iodine-stained grade C in previous examinations, active iodine application should be considered.