A colorectal polyp is a polyp (fleshy growth) occurring on the lining of the colon or rectum. Untreated colorectal polyps can develop into colorectal cancer.
Colorectal polyps are often classified by their behaviour (i.e. benign vs. malignant) or cause (e.g. as a consequence of inflammatory bowel disease). They may be benign (e.g. hyperplastic polyp), pre-malignant (e.g. tubular adenoma) or malignant (e.g. colorectal adenocarcinoma).
Colorectal polyps are not usually associated with symptoms. When they occur, symptoms include bloody stools; changes in frequency or consistency of stools (such as a week or more of constipation or diarrhoea); and fatigue arising from blood loss. Anemia arising from iron deficiency can also present due to chronic blood loss, even in the absence of bloody stools. Another symptom may be an increased mucus production especially those involving villous adenomas. Copious production of mucous causes loss of potassium that can occasionally result in symptomatic hypokalemia. Occasionally, if a polyp is big enough to cause a bowel obstruction, there may be nausea, vomiting and severe constipation.
Polyps are either pedunculated (attached to the intestinal wall by a stalk) or sessile (grow directly from the wall). In addition to the gross appearance categorization, they are further divided by their histologic appearance as tubular adenoma which are tubular glands, villous adenoma which are long finger like projections on the surface, and tubulovillous adenoma which has features of both.
Hereditary syndromes causing increased colorectal polyp formation include:
Familial adenomatous polyposis (FAP)
Hereditary nonpolyposis colorectal cancer
Peutz–Jeghers syndrome
Juvenile polyposis syndrome
Several genes have been associated with polyposis, such as GREM1, MSH3, MLH3, NTHL1, RNF43 and RPS20.
Familial adenomatous polyposis
Familial adenomatous polyposis (FAP) is a form of hereditary cancer syndrome involving the APC gene located on chromosome q521.
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
A sessile serrated lesion (SSL) is a premalignant flat (or sessile) lesion of the colon, predominantly seen in the cecum and ascending colon. SSLs are thought to lead to colorectal cancer through the (alternate) serrated pathway. This differs from most colorectal cancer, which arises from mutations starting with inactivation of the APC gene. Multiple SSLs may be part of the serrated polyposis syndrome. SSLs are generally asymptomatic. They are typically identified on a colonoscopy and excised for a definitive diagnosis and treatment.
A hyperplastic polyp is a type of colorectal polyp. Most hyperplastic polyps 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. Hyperplastic polyps on the right side of the colon do exhibit a malignant potential. This occurs through multiple mutations that affect the DNA-mismatch-repair pathways. As such DNA mutations during replication are not repaired.
Gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract (GI tract) and accessory organs of digestion, including the esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The symptoms relate to the organ affected and can include obstruction (leading to difficulty swallowing or defecating), abnormal bleeding or other associated problems. The diagnosis often requires endoscopy, followed by biopsy of suspicious tissue.
This course provides a comprehensive overview of the biology of cancer, illustrating the mechanisms that cancer cells use to grow and disseminate at the expense of normal tissues and organs.
Ce cours est une préparation intensive à l'examen d'entrée en 3ème année de Médecine. Les matières enseignées sont la morphologie macroscopique (anatomie) , microscopique (histologie) de la tête, du c
Colorectal cancer is the second-leading cause of cancer death worldwide. Early-stage disease can be detected with preventative medical screening and is treatable with surgical resection. Sixty-percent of patients, however, are diagnosed with advanced-stage ...
Transposable elements (TEs) are prevalent repeats in the human genome, play a significant role in the regulome, and their disruption can contribute to tumorigenesis. However, TE influence on gene expression in cancer remains unclear. Here, we analyze 275 n ...
Activin-A is a Transforming Growth Factor-B (TGFB)-related cytokine that regulates various biological processes including cell proliferation and differentiation through autocrine, paracrine or endocrine signaling. Activin-A expression is upregulated in mul ...