II. Types: General

  1. Benign
    1. Hyperplastic Colonic Polyp (except the higher risk, hyperplastic polyposis syndrome)
    2. Inflammatory Colonic Polyp
  2. Malignant Potential (require complete excision and close interval follow-up)
    1. Adenomatous Colonic Polyp
    2. Sessile Serrated Adenomatous Colonic Polyp

III. Types: Hyperplastic Polyp

  1. Account for 50% of sigmoid and rectal polyps
  2. Small (1-5 mm), sessile polyps
  3. Rare dysplasia risk (does not modify Colonoscopy screening intervals)

IV. Types: Adenomatous Polyp

  1. Tubular adenomas (80%)
    1. Malignant transformation rate: 4-8%
  2. Tubulovillous adenoma
    1. Malignant transformation rate: 19%
  3. Villous adenoma
    1. Malignant transformation rate: 38.4%

V. Types: Sessile Serrated Adenomatous Polyp

  1. Precautions
    1. Primary pathway to hypermethylated gene cancers (20-30% of Colorectal Cancer)
    2. Must be completely excised and monitored as with adenomatous polyps
    3. Easily missed on Colonoscopy (flat, indiscrete lesions with adherent mucus)
    4. Higher malignant potential when proximal to the sigmoid colon
  2. Characteristics
    1. Typically larger than 1 cm, but typically flat
    2. Occurs in right colon in 75% of patients
    3. More common in women (65%)
    4. Accounts for 9% of all Colonic Polyps
  3. References
    1. Larson (2008) Mayo Selected Topics in Internal Medicine, Lecture
    2. Snover (2005) Am J Clin Path 124:380 [PubMed]
    3. Spring (2006) Gastroenterology 131: 1400-7 [PubMed]

VI. Interpretation

  1. Factors suggesting higher risk of future adenomatous polyp (3 year follow-up)
    1. Three or more adenomatous polyps
    2. Adenomatous polyp or serrated polyp >1 cm
    3. Polyp biopsy consistent with high grade dysplasia or villous features
    4. Sessile serrated polyp with dysplasia
    5. Traditional serrated adenoma
  2. Factors suggesting lower risk of future adenomatous polyp (5-10 year follow-up)
    1. High quality baseline exam (see Colon Cancer Screening with Colonoscopy)
    2. Fewer than 3 adenomatous polyps
    3. Small adenomatous polyps <1 cm
    4. No high grade or villous changes
    5. Adenomatous polyps removed completely (not piecemeal)
  3. References
    1. Atkin (1992) N Engl J Med 326:658-62 [PubMed]
    2. Lieberman (2012) Gastroenterology 143(3): 844-57 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Colonic Polyps (C0009376)

Definition (CHV) an extra piece of tissue that grows in the large intestine, or colon
Definition (CHV) an extra piece of tissue that grows in the large intestine, or colon
Definition (CHV) an extra piece of tissue that grows in the large intestine, or colon
Definition (CHV) an extra piece of tissue that grows in the large intestine, or colon
Definition (CHV) an extra piece of tissue that grows in the large intestine, or colon
Definition (MEDLINEPLUS)

A polyp is an extra piece of tissue that grows inside your body. Colonic polyps grow in the large intestine, or colon. Most polyps are not dangerous. However, some polyps may turn into cancer or already be cancer. To be safe, doctors remove polyps and test them. Polyps can be removed when a doctor examines the inside of the large intestine during a colonoscopy.

Anyone can get polyps, but certain people are more likely than others. You may have a greater chance of getting polyps if you

  • Are over age 50
  • Have had polyps before
  • Have a family member with polyps
  • Have a family history of colon cancer

Most colon polyps do not cause symptoms. If you have symptoms, they may include blood on your underwear or on toilet paper after a bowel movement, blood in your stool, or constipation or diarrhea lasting more than a week.

NIH: National Institute of Diabetes and Digestive Diseases

Definition (NCI_NCI-GLOSS) Abnormal growths of tissue in the lining of the bowel. Polyps are a risk factor for colon cancer.
Definition (NCI) A polypoid lesion that arises from the colon and protrudes into the lumen. This group includes adenomatous polyps, serrated polyps, and hamartomatous polyps.
Definition (CSP) adenomatous colon polyps are considered to be precursor lesions of colon cancer.
Definition (MSH) Discrete tissue masses that protrude into the lumen of the COLON. These POLYPS are connected to the wall of the colon either by a stalk, pedunculus, or by a broad base.
Concepts Anatomical Abnormality (T190)
MSH D003111
ICD10 K63.5
SnomedCT 68496003, 188828009
LNC LA10557-9
English COLON POLYP, Polyp, Colonic, Polyps, Colonic, Colonic Polyps [Disease/Finding], Colonic Polyps, colon polyp, colon polyps, colonic polyps, Polyp(s);colon, polyp of colon, Polyp colon, Colon polyps, Colonic polyps, polyps of colon, polyps colon, polyps of colon (diagnosis), Colon polyp, -- Colon Polyps, Colonic polyp, Polyp of colon, Polyp of colon (disorder), colon; polyp, polyp; colon, Polyp of colon, NOS, Colonic polyp, NOS, Colonic Polyp, Colon Polyp, Polyp of Colon, Polyp of the Colon, colonic polyp
Swedish Tjocktarmspolyper
Czech kolon - polypy, Polyp tračníku
Finnish Koolonpolyypit
Korean 결장의 폴립
Polish Polipy okrężnicy
Norwegian Tykktarmspolypper, Polypper, kolon, Polypper, colon, Polypper, tykktarm, Kolonpolypper, Colonpolypper
Dutch colonpoliep, colon; poliep, poliep; colon, Poliep van colon, Colonpoliep, Poliep van de dikke darm, Poliep, colon-
French Polype du côlon, Polype colique, Polypes coliques, Polypes du côlon
German Kolonpolyp, Kolonpolypen
Hungarian Colon polyp
Italian Polipo del colon, Polipi del colon
Japanese ケッチョウポリープ, 結腸ポリープ
Portuguese Pólipo do cólon, Pólipos Colônicos, Pólipos do Cólon, Pólipos do Colo
Spanish Pólipo de colon, Polipos Colónicos, pólipo colónico, pólipo de colon (trastorno), pólipo de colon, Pólipos del Colon

Ontology: Adenomatous polyp of colon (C0850572)

Definition (NCI) An adenoma that arises from the colon. The group of colonic adenomas includes tubular, villous, and tubulovillous adenomas, traditional serrated adenomas, sessile serrated adenomas/polyps, and familial adenomatous polyposis.
Definition (NCI) A polypoid adenoma that arises from and protrudes into the lumen of the colon. Epithelial dysplasia is always present. According to the architectural pattern it is classified as tubular, tubulovillous, or villous.
Concepts Neoplastic Process (T191)
SnomedCT 428054006
Italian Adenoma del colon, Polipo adenomatoso del colon
English Colon Adenoma, Colonic Adenoma, Adenomatous colonic polyps, Adenomatous polyp of colon (disorder), Adenomatous polyp of colon, Colon adenomatous polyp, Adenoma;colon, colon (non-specific) polyp adenomatous, adenoma colon, adenomas colon, colon adenoma, adenomatous colon polyps, Colon adenoma, Adenomatous Polyp of Colon, Colon Adenomatous Polyp, Adenomatous Polyp of the Colon, Colonic Adenomatous Polyp, Adenomatous polyps, colon, Adenoma of Colon, Adenoma of the Colon, adenoma of the colon
Spanish pólipo adenomatoso de colon, pólipo adenomatoso de colon (trastorno), Pólipo adenomatoso en colon, Adenoma de colon
Czech Adenom tlustého střeva, Adenomatózní polyp tlustého střeva
Japanese 大腸腺腫, ダイチョウセンシュ, ダイチョウセンシュセイポリープ, 大腸腺腫性ポリープ
Portuguese Pólipo adenomatoso do cólon, Adenoma do cólon
French Polype adénomateux du côlon, Adénome du côlon
German Adenomatoeser Polyp des Color, Kolonadenom
Dutch adenomateuze colonpoliep, colonadenoom
Hungarian Vastagbél adenoma, Vastagbél adenomatosus polyp

Ontology: Adenoma of large intestine (C1302401)

Definition (NCI) An adenoma that arises from the colon or rectum. The group of colorectal adenomas includes tubular, villous, and tubulovillous adenomas, traditional serrated adenomas, sessile serrated adenomas/polyps, and familial adenomatous polyposis.
Concepts Neoplastic Process (T191)
SnomedCT 399432003
English adenoma of large intestine, adenoma of large intestine (diagnosis), Colorectal adenomas, Adenoma of large intestine (disorder), Adenoma of large intestine, Colorectal Adenoma, Adenoma of Large Bowel, Adenoma of Large Intestine, Adenoma of the Large Bowel, Adenoma of the Large Intestine, Large Bowel Adenoma, Large Intestine Adenoma
Spanish adenoma de intestino grueso (trastorno), adenoma de intestino grueso

Ontology: Colorectal Sessile Serrated Adenoma/Polyp (C2826783)

Definition (NCI) A polyp that arises from the colon or rectum. It is characterized by the presence of serrated glands and the absence of generalized dysplasia. Some authors have suggested that it is a precursor lesion for some colorectal adenocarcinomas with microsatellite instability.
Concepts Disease or Syndrome (T047)
English Colorectal SSA/P, Colorectal Mixed Hyperplastic Adenomatous Polyp/Serrated Adenoma, Colorectal Sessile Serrated Adenoma/Polyp, Colorectal SSA, Colorectal Sessile Serrated Polyp, Colorectal SSP, Colorectal Sessile Serrated Adenoma, Colorectal Mixed Hyperplastic Adenomatous Polyp