Over time, there is a risk for adenocarcinoma with ulcerative colitis. Here, more normal glands with abundant goblet cells are seen at the left, but the glands at the right are more irregular in shape and demonstrate dysplasia with darker crowded nuclei. Dsyplasia is the first indication that there is a move towards neoplasia.

Clinical findings can include diarrhea, but the amount of diarrheal stool is not great, and is often accompanied by tenesmus. Patients with prolonged UC are at increased risk for developing colon cancer. Colonic biopsy can be used to detect dysplasia, a neoplastic change in the mucosa which implies an increased probability of malignancy. Patients with UC are also at risk for development of liver diseases including sclerosing cholangitis and bile duct carcinoma.