The usefulness of magnifying endoscopy with narrow-band imaging to distinguish carcinoma in flat elevated lesions in the stomach diagnosed as adenoma by using biopsy samples

Background: Therapeutic strategies for flat elevated (0-IIa) lesions in the stomach diagnosed as adenoma by biopsy are currently not established, because some difficulties have previously been reported in the evaluation of vascular patterns alone for the differential diagnosis between adenoma and carcinoma. Objective: We attempted to evaluate the 0-IIa lesions diagnosed as adenoma by using magnifying endoscopy with narrow-band imaging (MENBI) to distinguish them as either adenoma or carcinoma. Setting: Department of Gastroenterology, Fujita Health University. Patients: Fourteen adenomatous lesions (6 adenomas and 8 carcinomas confirmed postoperatively) diagnosed with preoperative biopsies from patients who had undergone endoscopic submucosal dissection were evaluated. Interventions: We selected 5 sites per lesion for MENBI. Selected sites were divided into superficial structures (SSs) and irregular microvascular patterns (IMVPs). Main Outcome Measurements: The rate of SSs and IMVPs in adenoma and carcinoma. Results: Significant SSs were tubular in the adenoma and unclear in the carcinoma. Regarding IMVP subcategories, (1) slight intrastructual irregular microvascular patterns (ISIMVPs) accounted for 97%, (2) severe ISIMVPs accounted for 0%, (3) Fine networks accounted for 3%, and (4) corkscrews accounted for 0% of cases in the adenomas. The corresponding proportions in the carcinomas were (1) 40%, (2) 15%, (3) 45%, and (4) 0%. Severe ISIMVPs and fine networks were significant Findings for carcinomas. Limitations: The number of cases was limited. Conclusions: Our combined evaluation method using MENBI offers the ability to establish proper therapeutic strategies for lesions that are difficult to identify as adenoma or carcinoma.