The result will be reported according to the Bethesda system. All subjects with cytological diagnosis of atypia will be referred to Atrak clinic (a central clinic for upper gastrointestinal disease in Gonbad, Iran) for endoscopic examination. Endoscopic examination with Lugol's iodine staining will be performed by previously described methods and biopsies will be taken from abnormal lesions. Histological examination of endoscopic biopsy samples will be done by expert pathologists. If the results of the endoscopic examination show high-grade dysplasia or cancer, the subject will be referred for treatment. These subjects will be treated with endoscopic mucosal resection (EMR) and/or radiofrequency ablation (RFA).