Comparative analysis of avascular areas in superficial esophageal squamous cell carcinomas using in vivo and ex vivo magnifying endoscopy

BACKGROUND AND STUDY AIMS: An avascular area (AVA), one of the microvasculature changes in superficial esophageal cancers, appears when a tumor demonstrates a bulky growth pattern. We aimed to compare endoscopic and histopathological findings by observing formalin-fixed AVA specimens using magnifying endoscopy. PATIENTS AND METHODS: A prospective analysis was conducted on 16 patients with superficial esophageal cancer, including AVA, who underwent endoscopic submucosal dissection (ESD). Magnifying endoscopy and blue laser imaging were used to identify AVAs. After the ESD, the AVA width was measured on formalin-fixed specimens using magnifying endoscopy, and AVA thickness and depth were determined after hematoxylin and eosin staining using microscopy. RESULTS: Mean AVA widths of M1, M2, and M3/SM-lesions were 0.434, 0.578, and 0.835 mm, respectively (M1 vs. M2, P = 0.16; M2 vs. M3/SM-, P = 0.07). Mean AVA thicknesses of M1, M2, and M3/SM-lesions were significantly different (0.176, 0.518, and 0.800 mm; M1 vs. M2, P < 0.01; M2 vs. M3/SM-, P < 0.05). There was a significant correlation between AVA width and thickness. CONCLUSIONS: AVA size can be measured accurately on formalin-fixed specimens with magnifying endoscopy. AVA thickness can be useful for determining tumor depth.