| [ Summary ] |
It is not difficult to observe microvascular findings of colorectal tumors with the latest magnifying colonoscopy, because the mictovascular architecture of colorectal tumors is thicker than that of normal capillary rings. Submucosal massive invasive cancers display thicker micro-vessels with irregular size, shape, and distribution than adenomas, intramucosal or submucosal minimum invasive cancers. In contrast, some submucosal massive invasive cancers show thicker elongated micro-vessels with irregular size, shape, and distribution (long irregular vessel ; LIV). We previously presented the usefulness of this mode of magnified colonoscopic finding (LIV) for diagnosing the depth of submucosal invasion and vessel invasion of submucosal invasive colorectal cancers. We then investigated the relationship between the presence of LIV findings and the other two risk factors for lymph node metastasis (differentiation of histology and invasive front histology, so called sprouting). Submucosal invasive cancers with LIV findings significantly demonstrate poorer differentiation of histology and poorer invasive front histology than those without that finding. It is thought that magnified colonoscopic findings of LIV can predict risk factors of lymph node metastasis in submucosal invasive cancers. Colorectal tumors with such findings should not be removed endoscopically. In other words, such tumors must be treated surgically. Diagnosis of submucosal cancer by magnified colonoscopic findings of the microvascular architecture is useful and should be done simulataneously with pit pattern diagnosis. |