Potential and present limitation of endocytoscopy in the diagnosis of esophageal squamous-cell carcinoma: a multicenter ex vivo pilot study

Background: Endocytoscopy enables the in vivo observation of cellular nuclei in the GI tract. However, potential and present limitations of endocytoscopy have not been elucidated in detail. Objective: To investigate whether endocytoscopic images of cancerous and normal squamous cells in the esophagus correspond with horizontal histology of the mucosal surface. Design: An ex vivo pilot study. Setting: Multiple academic institutions. Materials: Endoscopically or surgically resected human esophagus obtained between May 2006 and July 2006. Interventions: Endocytoscopic observation was performed on small areas of cancerous lesions and corresponding normal squamous cells. Biopsy specimens were then retrieved from the areas scanned to make horizontal histologic sections. Main Outcome Measurements: Comparison of the images obtained by endocytoscopy and histology and comparison of the mean numbers of the total nuclei per endocytoscopic image obtained in cancerous and normal areas. Results: Twenty-seven esophageal squamous-cell carcinomas were acquired and evaluable pairs of an endocytoscopic image and a histological picture were obtained at 12 cancerous and 14 normal areas that showed similar morphologies between them. The mean (+/- SD) numbers of the total nuclei per image were 129 +/- 14.8 at the normal area and 550 +/- 66.5 at the cancerous area, respectively, which were significantly different between groups (P < .0001). Limitations: Only a comparison of cancerous and normal squamous cells in the esophagus at the ex vivo setting. Conclusions: Although endocytoscopic images closely correlated with conventional histology in the esophagus, appropriate preconditioning to constantly obtain sufficient image quality and universal criteria for endocytoscopic diagnosis of various diseases are essential before clinical application.