Hidden in Plain Sight: The Value of Ex Vivo Volumetric Laser Endomicroscopy in Confirming Neoplastic Changes Within a Barrettʼs Nodule

Abstract

Volumetric Laser Endomicroscopy (VLE) utilizes next generation optical coherence tomography to produce high-resolution cross-sectional imaging via a swept source laser. Usage to date has focused on the evaluation of Barrett's esophagus (BE), specifically identification of features consistent with dysplasia and neoplasia. A 66 year old male was referred for evaluation and treatment of BE found by his local gastroenterologist to have developed multi-focal low grade dysplasia between surveillance endoscopies in 2013 and 2016. The patient was scheduled for upper endoscopy with mapping BE biopsies. Key findings included a 3 cm hiatal hernia and a BE segment classified as C2-M3 by Prague criteria. Within this segment was a subcm nodule located 1 cm proximal to the top of the gastric folds (Figure 1). VLE of the distal esophagus revealed diffuse loss of normal wall layer architecture, consistent with BE, along with a focal area of abnormal epithelial glands suspicious for dysplasia located on the opposite wall from the nodule. The region near the nodule contained a topographical surface, but no clear suspicious glands were appreciated. The nodule then was resected using a cap-band-ligator with snare mucosectomy technique. An ex vivo VLE scan was performed on the nodule. Images demonstrated multiple areas of markedly abnormal-appearing epithelial glands with some containing what appeared to be necrotic material. These changes were suspicious for high grade dysplasia (Figure 2).Figure 1Figure 2Figure 3Pathology from the resected specimen showed extensive BE with high grade dysplasia. Comparison of the tissue sample and the ex vivo VLE images confirmed a very similar morphologic appearance in both specimens. This case highlights how the limitations of in vivo VLE when nodularity is present to distort normal esophageal anatomy can be overcome through use of the technology following endoscopic resection. The topographical nature of the nodule prevented optimal tissue contact with the VLE probe, resulting in suboptimal in vivo visualization of the highly irregular glandular structures contained within the nodule. Routine use of this technology following resection, especially when images are compared with pathology specimens, can provide confirmation that the appropriate region of concern has been removed from the esophagus.