Relatively . Slowly. Usually from a single cell to a polyps the size of a pencil eraser takes 2-3 years, but there can be a wide degree of variability in both benign and malignant polyps.
Usually slowly. Polyps generally grow slowly, taking years to get big enough to be visible. However, there do seem to be some that are faster growing and more aggressive. I have certainly seen them show up in less than a year after a previous colonoscopy.
Abnormal gowths . Neoplasia is a general term to describe abnormal growth pattern, cancer-like, unregulated by normal bodily control systems. Some colon polyps are destined to become cancerous, some are not, so all polyps are usually removed when they are found so we can distinguish the difference under the microscope, not by appearance which can fool you. Read more...