Contents 1 Signs and symptoms 2 Structure 3 Genetics 3.1 Familial adenomatous polyposis 3.2 Hereditary nonpolyposis colorectal cancer (Lynch Syndrome) 3.3 Peutz–Jeghers syndrome 3.4 Juvenile polyposis syndrome 4 Types 4.1 Comparison table 4.2 Hyperplastic polyp 4.3 Neoplastic polyp 4.3.1 Adenomas 4.4 Hamartomatous polyp 4.5 Inflammatory polyp 5 Diagnosis 5.1 Gallery 5.2 NICE classification 6 Prevention 7 Treatment 8 References 9 External links Signs and symptoms [ edit ] Colorectal polyps are not usually associated with symptoms. [2] When they occur, symptoms include bloody stools ; changes in frequency or consistency of stools (such as a week or more of constipation or diarrhoea ); [3] and fatigue arising from blood loss. [2] Anemia arising from iron deficiency can also present due to chronic blood loss, even in the absence of bloody stools. [3] [4] Another symptom may be an increased mucous production especially those involving villous adenomas. [4] Copious production of mucous causes loss of potassium that can occasionally result in symptomatic hypokalemia. [4] Occasionally, if a polyp is big enough to cause a bowel obstruction , there may be nausea , vomiting and severe constipation. [3] Structure [ edit ] Polyps are either pedunculated (attached to the intestinal wall by a stalk) or sessile (grow directly from the wall). [5] [6] : 1342 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. [6] : 1342 Genetics [ edit ] 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 . [7] Familial adenomatous polyposis [ edit ] Main article: Familial adenomatous polyposis Familial adenomatous polyposis (FAP) is a form of hereditary cancer syndrome involving the APC gene located on chromosome q521. [8] The syndrome was first described in 1863 by Virchow on a 15-year-old boy with multiple polyps in his colon. [8] The syndrome involves development of multiple polyps at an early age and those left untreated will all eventually develop cancer. [8] The gene is expressed 100% in those with the mutation and it is autosomal dominant. [8] 10% to 20% of patients have negative family history and acquire the syndrome from spontaneous germline mutation. [8] The average age of newly diagnosed patient is 29 and the average age of newly discovered colorectal cancer is 39. [8] It is recommended that those affected undergo colorectal cancer screening at younger age with treatment and prevention are surgical with removal of affected tissues. [8] Hereditary nonpolyposis colorectal cancer (Lynch Syndrome) [ edit ] Main article: Hereditary nonpolyposis colorectal cancer Hereditary nonpolyposis colorectal cancer (HNPCC, also known as Lynch syndrome) is an hereditary colorectal cancer syndrome. [8] It is the most common hereditary form of colorectal cancer in the United States and accounts for about 3% of all cases of cancer. [8] It was first recognized by Alder S. Warthin in 1885 at the University of Michigan. [8] It was later further studied by Henry Lynch who recognized an autosomal dominant transmission pattern with those affected having relatively early onset of cancer (mean age 44 years), greater occurrence of proximal lesions, mostly mucinous or poorly differentiated adenocarcinoma, greater number of synchronous and metachronous cancer cells, and good outcome after surgical intervention. [8] The Amsterdam Criteria was initially used to define Lynch syndrome before the underlying genetic mechanism had been worked out. [8] The Criteria required that the patient has three family members all first-degree relatives with colorectal cancer that involves at least two generations with at least one affected person being younger than 50 years of age when the diagnosis was made. [8] The Amsterdam Criteria is too restrictive and was later expanded to include cancers of endometrial, ovarian, gastric, pancreatic, small intestinal, ureteral, and renal pelvic origin. [8] The increased risk of cancer seen in patients with by the syndrome is associated with dysfunction of DNA repair mechanism. [8] Molecular biologists have linked the syndrome to specific genes such as hMSH2, hMSH1, hMSH6, and hPMS2. [8] Peutz–Jeghers syndrome [ edit ] Main article: Peutz–Jeghers syndrome Peutz–Jeghers syndrome is an autosomal dominant syndrome that presents with hamartomatous polyps, which are disorganized growth of tissues of the intestinal tract, and hyperpigmentation of the interlining of the mouth, lips and fingers. [8] The syndrome was first noted in 1896 by Hutchinson, and later separately described by Peutz, and then again in 1940 by Jeghers. [8] The syndrome is associated with malfunction of serine-threonine kinase 11 or STK 11 gene, and has a 2% to 10% increase in risk of developing cancer of the intestinal tract. [8] The syndrome also causes increased risk of extraintestinal cancer such as that involving breast, ovary, cervix, fallopian tubes, thyroid, lung, gallbladder, bile ducts, pancreas, and testicles. [8] The polyps often bleeds and may cause obstruction that would require surgery. [8] Any polyps larger than 1.5 cm needs removal and patients should be monitored closely and screen every 2 years for malignancy. [8] Juvenile polyposis syndrome [ edit ] Main article: Juvenile polyposis syndrome Juvenile polyposis syndrome is an autosomal dominant syndrome characterized by increased risk of cancer of intestinal tract and extraintestinal cancer. [8] It often presents with bleeding and obstruction of the intestinal tract along with low serum albumin due to protein loss in the intestine. [8] The syndrome is linked to malfunction of SMAD4 a tumor suppression gene that is seen in 50% of cases. [8] Individuals with multiple juvenile polyps have at least 10% chance of developing malignancy and should undergo abdominal colectomy with ileorectal anastomosis, and close monitoring via endoscopy of rectum. [8] For individuals with few juvenile polyps, patients should undergo endoscopic polypectomy. [8] Types [ edit ] Incidences and malignancy risks of various types of colorectal polyps. ... Hamartomatous polyps are often found by chance; occurring in syndromes such as Peutz–Jegher syndrome or Juvenile polyposis syndrome. Peutz–Jeghers syndrome is associated with polyps of the GI tract and also increased pigmentation around the lips, genitalia, buccal mucosa feet and hands. ... ISBN 978-0-7817-7942-5 . [ page needed ] ^ Calva, Daniel; Howe, James R (2008). "Hamartomatous Polyposis Syndromes" . Surgical Clinics of North America . 88 (4): 779–817, vii. doi : 10.1016/j.suc.2008.05.002 .
ALOX5,
ILK,
TRPM7,
HDAC2,
PMS2,
PTEN,
PPARG,
CDX2,
APC,
TP53,
IGF1,
CTNNB1,
BRAF,
MGMT,
MLH1,
KRAS,
PROM1,
CYSLTR1,
PER2,
ABI1,
DKK1,
MFAP5,
KL,
PLK2,
GREM1,
SATB2,
CXCR4,
FOXD3,
ACAD8,
ACKR3,
TET1,
MUC16,
SLCO6A1,
GSTK1,
MIR137,
MIR18A,
MIR182,
MIR19B1,
MIR200C,
MIR135B,
NTT,
AHR,
WT1,
GSTM1,
BRCA1,
RUNX3,
CD80,
CD86,
CCN2,
DCN,
EGF,
EGFR,
ERBB3,
GH1,
FFAR2,
GSTP1,
VDR,
GUCA2A,
GUCA2B,
IGFBP2,
IL1B,
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ODC1,
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PTGS2,
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