[A comparative study of endoscopic image stained by iodine and histopathology in early esophageal cancer and precancerous lesions (dysplasia)].

Objective: The aim of this study is to evaluate the relationship between the imaging patterns of endoscopy aided by iodine stain and histological diagnosis.

Methods: A balloon cytological screening was conducted in 4000 participants in high-risk area of esophageal cancer in 1997-1998, 1050 out of these 4000 participants were confirmed as abnormal by cytology. Among them, 867 were given endoscopy examination during which mucosal stain with 1.2% iodine solution was used. The stain images were graded as four categories: Grade 1, dark yellow, protruding inlay-like with clear borders and showing pink after discoloration; Grade 2, between grade 1 and grade 3; Grade 3, light yellow, flat lesion with clear but not sharp borders and Grade 4, dark-brown color. According to the above criteria, the lesions were recorded and graded after the examination. The biopsies were taken from the unstained lesions and underwent pathologic evaluation. A comparison between the imaging patterns of endoscopy aided by iodine stain and histological diagnosis was evaluated. The correlation coefficient was estimated using Spearman's Rank Correlation.

Results: 94.4% (68/72) of the superficial carcinoma and severe dysplasia, 61.8% (73/118) of moderate dysplasia and 27.7% (35/126) of mild dysplasia were distributed in the grade 1 and grade 2 of iodine stain images of which the patterns conforming to the principle and rule of formation of the image by iodine stain.

Conclusion: There is close relationship between the imaging patterns of endoscopy aided by iodine stain and histological diagnosis. The magnitude of exposure of the malignant tissue is the pathologic basis of formation of various images by iodine stain. Iodine stain greatly helps of early detection of esophageal cancer.