The study of dynamic chemical magnifying endoscopy in gastric neoplasia.

BACKGROUND: We assessed the usefulness of acetic acid-enhanced magnifying endoscopy in the diagnosis of gastric neoplasia.
METHODS: Forty-five patients (27 men, 18 women; median age 61.6 years) with gastric carcinoma or adenoma were enrolled in a prospective trial of enhanced magnifying endoscopy after instillation of 1.5% acetic acid. Acetic acid-enhanced magnified views of carcinoma or adenoma and the surrounding non-neoplastic mucosa were observed, and the duration of whitening time of each lesion was recorded. OBSERVATIONS: Magnified views of carcinoma showed a minute, grain-like pattern that differed from the surrounding noncancerous mucosa. The histopathologic diagnostic criteria were based on the Vienna classification of GI epithelial neoplasia. The mean duration of whitening differed with each histologic type: low-grade adenoma, 94 seconds; high-grade adenoma, 24.3 seconds; noninvasive carcinoma, 20.1 seconds; invasive intramucosal carcinoma, 3.5 seconds; and submucosal carcinoma or beyond, 2.5 seconds. The duration in the non-neoplastic surrounding mucosa was 90 seconds. After the disappearance of whitening in the carcinoma, the irregular pattern of the carcinoma reappeared, and the contrast between carcinomatous microvessels and the whitened non-neoplastic tissue became very clear on magnifying endoscopy. In accordance with the duration of whitening, more than 1 minute was termed "continuous whitening," from 31 to 60 seconds was "delayed disappearance of whitening," from 30 to 6 seconds was "early disappearance of whitening," and 0 to 5 seconds was "no response."
CONCLUSIONS: Acetic acid-enhanced magnifying endoscopy was useful for the diagnosis of gastric adenocarcinoma. The duration of whitening differed among grades of neoplasia, and it was possible to observe changes in the whitening with time. Acetic acid-enhanced magnifying endoscopy, therefore, can be termed "dynamic chemical magnifying endoscopy."