3534 High grade dysplasias are present in normal appearing esophageal mucosa in subjects at risk for squamous cell carcinoma in southern brazil.

Objectives: Subjects at risk for squamous cell carcinoma of the esophagus were examined for mucosal abnormalities that could contain high grade dysplasias and/or early cancer with upper gastrointestinal endoscopy. Methods: Individuals found with cytology atypias at a screening program using esophageal balloon were submitted to esophagoscopy and the mucosa examined before and after Lugol spraying and biopsies obtained from unstained and stained areas. Results: 1495 subjects were screened and 122 underwent endoscopy. Their mean age was 57,8 and 75 (61.5%) were males. They were exposed, daily, to known risk factors as hot mate infusion drinking (91%), cigarrette smoking (51.6%) and alcohol drinking (19.7%). Conventional esophagoscopy visualized minute mucosal lesions (focal hyperemia, erosion, ulceration, nodule, depression / elevation, white plaque, red focal area) in 78 (63.9%) subjects but it was normal in 44 (36.1%). After Lugol spraying unstained areas were seen in 82 (67.2 %) individuals, 61 of which localized in mucosa with normal appearance with biopsies disclosing 10 dysplasias ( 5 high and 5 low grade) while 21, coincident with visible abnormalities had adenocarcinoma in one and a low grade dysplasia in another. Stained mucosa were also biopsied randomly in all subjects and 2 dysplasias were found (1 high and 1 low grade). Lugol esophagoscopy unstained areas had sensitivity of 83.3%, specificity of 61.1 %, positive predictive value of 6.09% and negative predictive value of 99.1% to detect high grade dysplasias ( p=0.03, Fisher's exact test). All high grade dysplasias were present in normal appearing esophageal mucosa. Conclusions: High grade dysplasias were occult in normal appearing mucosa and most were detected only after addition of Lugol staining to the esophageal mucosa.