Epidermoid metaplasia of the esophagus: endoscopic feature and differential diagnosis.

BACKGROUND/AIMS: Despite the recent improvement of endoscopic diagnostic accuracy, there remain many undiscovered lesions in the GI tract. One such lesion is epidermoid metaplasia of the esophagus. The aim of this study is to clarify the endoscopic and pathological characteristics of epidermoid metaplasia of the esophagus.
METHODOLOGY: We reviewed all histological records of gastrointestinal endoscopic biopsy specimens obtained in our institution from September 2003 to August 2006 and identified five lesions from four patients with characteristic pathological findings of epidermoid metaplasia.
RESULTS: All four patients were heavy drinkers and had a synchronous or metachronous squamous cell carcinoma. Three of them had multiple lugol-voiding lesions in the background esophageal mucosa. Endoscopic examination revealed common findings in these lesions: clear demarcation, slightly elevated shape, translucent white color, scaly or shaggy surface, and unstained appearance after Lugol's iodine staining. These endoscopic findings resembled those of superficial esophageal cancer. The pathological features of these lesions were uniform in hyperkeratotic and distinct granular layers of the epithelium and were very similar to those of normal epidermis of the skin.
CONCLUSIONS: Since the endoscopic features of epidermoid metaplasia resemble those of superficial esophageal cancer, we must pay enough attention to this new entity at the endoscopic examination.