Incidences and malignancy risks of various types of<unk> s.<unk> s can broadly be classified as follows: * hyperplastic, * neoplastic (adenomatous & malignant), * hamartomatous and, * inflammatory. Comparison table +<unk> s Type Risk of containing malignant cells Histopathology Image Hyperplastic<unk>  0% No dysplasia. * Mucin-rich type: Serrated (“saw tooth”) appearance, containing glands with star-shaped lumina. Crypts that are elongated but straight, narrow and hyperchromatic at the base. All crypts reach to the muscularis mucosae. * Goblet cell-rich type: Elongated, fat crypts and little to no serration. Filled with goblet cells, extending to surface, which commonly has a tufted appearance. 180px Tubular adenoma 2% at 1.5 cm Low to high grade dysplasia Over 75% of volume has tubular appearance. 180px Tubulovillous adenoma 20% to 25% 25%-75% villous 180px Villous adenoma 15% to 40% Over 75% villous 180px Sessile serrated adenoma (SSA) * Basal dilation of the crypts * Basal crypt serration * Crypts that run horizontal to the basement membrane (horizontal crypts) * Crypt branching. 180px<unk>  adenocarcinoma 100% * In carcinoma in situ (Tis): cancer cells invading into the lamina propria, and may involve but not penetrate the muscularis mucosae. Can be classified as "high-grade dysplasia", because prognosis and management are essentially the same. * Invasive adenocarcinoma: Extending through the muscularis mucosae into the submucosa and beyond. 180px Hyperplastic<unk>  Most hyperplastic<unk> s are found in the distal colon and rectum. They have no malignant potential, which means that they are no more likely than normal tissue to eventually become a cancer. Neoplastic<unk>  A neoplasm is a tissue whose cells have lost normal differentiation. They can be either benign growths or malignant growths. The malignant growths can either have primary or secondary causes. Adenomatous<unk> s are considered precursors to cancer and cancer becomes invasive once malignant cells cross the muscularis mucosa and invade the cells below. Any cellular changes seen above the lamina propria are considered non-invasive and are labeled atypia or dysplasia. Any invasive carcinoma that has penetrated the muscularis mocos has the potential for lymph node metastasis and local recurrence which will require more aggressive and extensive resection. The Haggitt's criteria is used for classification of<unk> s containing cancer and is based on the depth of penetration. The Haggitt's criteria has level 0 through level 4, with all invasive carcinoma of sessile<unk>  variant by definition being classified as level 4. * Level 0: Cancer does not penetrate through the muscularis mucosa. * Level 1: Cancer penetrates through the muscularis mucosa and invades the submucosa below but is limited to the head of the<unk> . * Level 2: Cancer invades through with involvement of the neck of<unk> . * Level 3: Cancer invades through with involvement of any parts of the stalk. * Level 4: Cancer invades through the submucosa below the stalk of the<unk>  but above the muscularis propria of the bowel wall. Adenomas Neoplastic<unk> s of the bowel are often benign hence called adenomas. An adenoma is a tumor of glandular tissue, that has not (yet) gained the properties of cancer. The common adenomas of the colon<unk>  adenoma) are the tubular, tubulovillous, villous, and sessile serrated (SSA). A large majority (65% to 80%) are of the benign tubular type with 10% to 25% being tubulovillous, and villous being the most rare at 5% to 10%. As is evident from their name, sessile serrated and traditional serrated adenomas (TSAs) have a serrated appearance and can be difficult to distinguish microscopically from hyperplastic<unk> s. Making this distinction is important, however, since SSAs and TSAs have the potential to become cancers, while hyperplastic<unk> s do not. The villous subdivision is associated with the highest malignant potential because they generally have the largest surface area. (This is because the villi are projections into the lumen and hence have a bigger surface area.) However, villous adenomas are no more likely than tubular or tubulovillous adenomas to become cancerous if their sizes are all the same. Hamartomatous<unk>  Hamartomatous<unk> s are tumours, like growths found in organs as a result of faulty development. They are normally made up of a mixture of tissues. They contain mucus-filled glands, with retention cysts, abundant connective tissue, and chronic cellular infiltration of eosinophils. They grow at the normal rate of the host tissue and rarely cause problems such as compression. A common example of a hamartomatous lesion is a strawberry naevus. Hamartomatous<unk> s are often found by chance; occurring in syndromes such as Peutz–Jegher syndrome or Juvenile<unk> osis syndrome. Peutz–Jeghers syndrome is associated with<unk> s of the GI tract and also increased pigmentation around the lips, genitalia, buccal mucosa feet and hands. People are often diagnosed with Peutz-Jegher after presenting at around the age of 9 with an intussusception. The<unk> s themselves carry little malignant potential but because of potential coexisting adenomas there is a 15% chance of colonic malignancy. Juvenile<unk> s are hamartomatous<unk> s that often become evident before twenty years of age, but can also be seen in adults. They are usually solitary<unk> s found in the rectum which most commonly present with rectal bleeding. Juvenile<unk> osis syndrome is characterised by the presence of more than five<unk> s in the colon or rectum, or numerous juvenile<unk> s throughout the gastrointestinal tract, or any number of juvenile<unk> s in any person with a family history of juvenile<unk> osis. People with juvenile<unk> osis have an increased risk of colon cancer. Inflammatory<unk>  These are<unk> s that are associated with inflammatory conditions such as ulcerative colitis and Crohn's disease.
Colorectal polyp
Colorectal adenoma
Anal dysplasia
Anorectal varices
Gastric varices
Anal fistula
Callous ulcer
Reactive gastropathy