Abstract
Iodine staining is mainly performed to screen for superficial esophageal cancer and to evaluate the extent of lesions. The normal esophageal mucosa stained with iodine consisted of aggregations of papillary patterns with small white spots. Changes in the color tone of iodinestain reflect the thickness and degree of damage of the prickle-cell layer, which reacts with iodine. Whitish thickened areas of reflex esophagitis were darkly stained with iodine. Red regions retained their papillary structures and were unstained with iodine and poorly demarcated. Unstained regions suggestive of cancer are characterized by irregular positively stained areas of various sizes within a poorly demarcated unstained region. Dense aggregates of abnormal vessels proliferate up to near the surface. As iodine staining fades, the lesion becomes redder than the surround region, often resulting in positive pink-color signs. Pink-color signs also become positive when papillary vessel proliferation is caused by inflammation. The regions with chronic inflammation and repeated cellular regeneration may be difficult to distinguish from cancer. Basal-layer-type CIS present with poorly demarcated areas unstained with iodine. PC signs are often negative. Papillary structures of different sizes and the formation of poorly demarcated regions can be used to distinguish CIS from inflammatory disease. Iodine staining properties and microvascular patterns should be evaluated to diagnose CIS as well as inflammatory lesions.
