Microvascular architecture of early esophageal neoplasia.

Progress in magnifying endoscopy has allowed endoscopic atypia to be evaluated on the basis of the presence or the absence of microvascular hyperplasia in a tumor. We focused our attention on intra-epithelial papillary capillary loops (IPCLs) and studied 20 cases of esophageal neoplasia (IPCL type III, 10 cases; IPCL type IV, 10 cases) and 99 vessels (IPCL type III, 24 vessels; IPCL type IV, 75 vessels). We evaluated the histopathological findings and measured vessel caliber, distance from the basement membrane, distance between blood vessels and thickness of the epithelium. According to the Vienna classification, the histological findings in the 10 patients with IPCL type III lesions were classified as category 1 (negative for neoplasia/dysplasia) in 8 patients and category 3 (non-invasive low grade neoplasia) in 2 patients. The histological findings in the 10 patients with IPCL type IV lesions were classified as category 1 in 1 patient, category 3 in 4 patients and category 4 (non-invasive high grade neoplasia) in 5 patients. The vessel caliber of IPCL type IV lesions (mean, 5.9 ± 2.7 µm) was significantly larger than that of IPCL type III lesions (mean, 4.8 ± 1.5 µm) (P=0.013). The distance from the basement membrane of IPCL type IV lesions (mean, 99.9 ± 34.4 µm) was significantly greater than that of IPCL type III lesions (mean, 58.0 ± 36.2 µm) (P=1.52562E-06). The distance between blood vessels and the thickness of the epithelium did not differ significantly between IPCL type III and IPCL type IV lesions. Our results revealed that changes in vessels of IPCL type IV lesions involve two factors: increased vessel caliber and prolongation of IPCLs toward the surface. These vascular changes appear to be associated with increased atypia of blood vessels.