Abstract
Although endoscopic ultrasonography is useful for assessing the internal echo-pattern of colorectal submucosal tumors, there have been few studies of the echo-pattern of colorectal villous tumors using this method. The aim of this study was to evaluate the characteristics of image of villous tumors using endoscopic ultrasonography. Endoscopic ultrasonography was performed on 120 patients with colorectal neoplasms, including 10 adenomas and 110 carcinomas. These neoplasms were classified histologically into three groups according to the extent of the villous component: villous, 9 cases, tubulovillous, 25 cases, and non-villous, 86 cases. Villous tumors were defined as either villous or tubulovillous lesions. Endoscopic ultrasonography findings were compared with histological findings. The echo-patterns of villous tumors frequently contained multicystic regions. The incidence of this echo-pattern was significantly different between villous tumors (27/34; 79%) and non-villous tumors (7/86 ; 8%) . Distribution of the cystic regions differed among the neoplasms with diffuse distribution observed in all (9/9) villous lesions, 20% (5/25) of tubulovillous lesions and none of non-villous lesions. Focal distribution was observed in none (0/9) of the villous lesions, 52% (13/25) of the tubulovillous lesions and 8 % (7/86) of the non-villous lesions. There was a significant difference in the distribution of the cystic regions between villous and tubulovillous lesions. We were able to identify endoscopic ultrasonography features specific to villous tumors, and show that endoscopic ultrasonography is useful for detecting colorectal villous tumors based on the cystic echo-pattern.
