Efficacy of acetic acid-spraying method in diagnosing extension of barrett's cancer under the squamous epithelium

Aim:  Endoscopic diagnosis of the lateral extension of Barrett's cancer under the squamous epithelium (BCUS) is sometimes difficult because the cancer is unobservable in the esophageal lumen. The aim of the present study was to clarify the endoscopic features of the extension of BCUS and verify the usefulness of the acetic acid-spraying method (AAS) for diagnosis. Methods:  A total of 25 patients with Barrett's cancer who had undergone endoscopic resection were included in this study. Histological examination of patients' resected specimens was performed to identify the presence of BCUS. Then, the endoscopic images of the BCUS cases were reviewed to summarize the findings and to evaluate the feasibility of diagnosing the extent of BCUS with each imaging technique. Results:  Of the 25 patients, 10 (40%) had BCUS. With white-light imaging, subtle reddish change was observed in the area of BCUS in 80% of the patients, and a flat elevated lesion was recognized in 30%. With narrow band imaging, slight brownish change was observed in the area of BCUS in 86% of the patients. Slight white changes were visualized in all cases with AAS. The extension of BCUS was correctly diagnosed by white-light imaging, narrow band imaging and AAS in 50%, 43% and 100% of the cases, respectively. Histology verified the opening of cancerous glands, which extended under the squamous epithelium, into the esophagus in the area showing slight white changes by AAS. Conclusion:  AAS can be useful for diagnosing the extension of BCUS.