Hello my friend I am Dr. Arianisa Thanks for your question on HCM I can understand your concern very well. Adenomas are common. Most are small, usually less than a centimetre in diameter, but sometimes they are bigger. There is a small risk that an adenoma may, in time, become cancerous. If one does turn cancerous, the change usually takes place after a number of years. Most bowel cancers (colorectal cancers) develop from a polyp that has been present for 5-15 years. (In other words, although most adenomas do not become cancerous, the vast majority of cancers in the bowel initially develop from an adenoma that has been present for a number of years.) It is difficult to be certain of the exact risk of developing cancer from an adenoma. One study suggested that for a single 1 cm adenoma, the risk of it turning cancerous was about 1 in 12 after 10 years, and about a 1 in 4 after 20 years. However, risk seems to vary depending on factors such as the size of the adenoma, and its exact subtype. Some subtypes are more prone to develop into bowel cancer than others. The treatment :you will usually be advised to have it removed, even if it is causing no symptoms. This is to prevent the (small) risk of it developing into a cancer at some point in the future. Your doctor will advise on the need for follow-up. This may depend on factors such as the size of the polyp, the exact subtype and laboratory report, and your age. Once these factors are considered, some people are advised to have a routine colonoscopy at some point in the future. Hope you get well and this information is helpful too Best regards