| [ Summary ] |
Colorectal cancer is one complication from ulcerative colitis (UC). In some UC cases, it has been shown that dysplasia develops as a precursor to colorectal cancer. Dysplasia is classified as high-grade dysplasia (HGD) or low-grade dysplasia (LGD). When it is found in polypoid lesions, it is termed “DALM” (dysplasia associated lesion or mass), which is a high-risk marker for colorectal cancer. Generally, HGD or DALM are considered to be surgical indications for total proctocolectomy. However, there is still some controversy as how to deal with LGD, when it is found from the flat mucosa of the colon or rectum. This is because the natural history of LGD has not been fully elucidated. It has been suggested that LGD in the flat mucosa is a surgical indication, however, some claim that patients with LGD should undergo periodic surveillance colonoscopy instead of total proctocolectomy. If patients with LGD in the flat mucosa are to be followed up on carefully, it is essential that close examinations be performed, in order to prevent progression of the lesions into the advanced stages, in which curative resection cannot be performed. |