超声内镜下大肠黏膜下癌的高频声像特征

High- frequency endoscopic sonography of submucosal tumors of the large intestine

Objective] The aim of this study was to evaluate the role of miniprobe ultrasonography on colonoscope in the diagnosis of submucosal tumor of the large intestine and determine it's imaging characteristic. Methods] Thirty- five patients with submucosal tumors of the large intestine underwent miniprobe (Olympus UM -2R,12 MHz; UM -3R, 20 MHz) ultrasonography on colonoscope. The results were compared with pathological findings of specimens by biopsy and surgical resection. Results] Lipomas were visualized as hyperechoic homogeneous masses located in the submucosa with a distinct border. Leiomyomas were visualized as hypoechoic homogeneous mass originated from the muscularis propria. Leiomyosarcomas were shown with inhomogeneous echo and irregular border.Carcinoids waere presented as a submucosal hypoechoic mass with a homogenous echo and distinct border. Lymphangiomas were shown as submocosal hypoechoic masses with cystic septal structures. Malignant lymphomas displayed as hypoechoic mass from mucosa to muscularis propria, while pneumatosis cystoids intestinalis originated from submucosa with a special sonic shadow. One large leiomyoma was misdiagnosed as leiomyosarcoma. Conclusion ]Endoscopic miniprobe ultrasonography can provide precise information about the size, layer of origin, border and has a high accuracy in the diagnosis of submucosal tumor of the large intestine. Pre - operative miniprobe ultrasonography on colonoscope may play an important role in the choice of therapy for submucosal tumor of the large intestine.