Changes in the microvascular structure of mucosal squamous cell carcinoma of the esophagus and their significance in tumor progression.

22.32, and 27.08 µm, respectively, for M1, M2 and M3, respectively (M1:M2 P < 0.05, M2:M3 P < 0.01). Conclusions: During tumor stage progression, a high-volume blood demand and cancer cell overgrowth to occupy the laminar propria mucosa (LPM) cause obvious elongation, thickening, branching, irregularity and deformity of the IPCL, which were characteristics of M3 lesions. The results of the present study support and can be applied with the current Japanese classification for improving the diagnostic accuracy, especially to differentiate between M2 and M3 lesions based on the endoscopic findings.