polyp

(redirected from colonic polyp)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to colonic polyp: colon cancer, colonoscopy, dysphagia

polyp,

in medicine, a benign tumor occurring in areas lined with mucous membrane such as the nose, gastrointestinal tract (especially the colon), and the uterus. Some polyps are pedunculated tumors, i.e., they grow on stems; others, attached by a broad base, are called sessile. Nasal polyps are usually associated with an allergic condition; since they interfere with breathing, it is advisable that they be removed. Uterine and gastrointestinal polyps are likely to cause bleeding, but, more important, they may undergo malignant degeneration and for this reason are also usually removed.

Polyp

 

a morbid growth that develops on mucosa of the respiratory tract, uterus, stomach, large intestine, rectum, and urinary bladder. Polyps are villous formations of various shapes; sometimes pear-shaped, they are usually broad-based or pedunculated. They may ulcerate and cause hemorrhages. Modern medical practice considers polyps precancerous, and therefore they are surgically removed.


Polyp

 

the common name for the predominantly benthic form of coelenterates. In metagenetic forms, that is, in hydrozoans (except hydras) and scyphozoans, polyps are capable only of vegetative reproduction, forming either medusae (in hydrozoans by budding, in scyphozoans by transverse division) or other polyps. Sexual reproduction is characteristic in such forms only in individuals of the medusa phase—free-swimming individuals or individuals remaining attached to the polyp. In homogenetic forms (hydrida and anthozoans), the polyps are capable of both sexual and vegetative reproduction. With sexual reproduction, larvae develop from the eggs and are transformed into polyps.

Polyps usually are cylindrical and measure from several millimeters to several centimeters tall (rarely up to 1 m). The upper part of the body contains the mouth, which is surrounded by tentacles. The base serves as a foot by which the polyp attaches itself to the substrate (in solitary forms) or to the colony (in colonial forms). There is often a hard external or internal skeleton of organic matter or limestone. The nervous system, which is developed considerably less than in the medusa, is in the form of a subepithelial nerve ganglion. Sex glands are present only in homogenetic forms and are located in the ectoderm (in Hydrida) or in the entoderm (in anthozoans). Sexual products are eliminated through ruptures in the walls of the gonads. In rare cases (in some actiniae), development occurs in the gastral cavity of the maternal body.

Polyps, except for hydras and a few related forms, are marine organisms. The majority lead a sedentary life; many form colonies. Movements are limited by the extension and contraction of the body and tentacles. Some solitary forms, hydras and actiniae, move slowly along the substrate; a few actiniae inhabit the depths. Polyps feed predominantly on animal substances, usually capturing their prey with their tentacles.

REFERENCES

See references under COELENTERATA.

D. V. NAUMOV

polyp

[′päl·əp]
(invertebrate zoology)
A sessile cnidarian individual having a hollow, somewhat cylindrical body, attached at one end, with a mouth surrounded by tentacles at the free end; may be solitary (hydra) or colonial (coral).
(medicine)
A smooth, rounded or oval mass projecting from a membrane-covered surface.

polyp

1. Zoology one of the two forms of individual that occur in coelenterates. It usually has a hollow cylindrical body with a ring of tentacles around the mouth
2. Pathol a small vascularized growth arising from the surface of a mucous membrane, having a rounded base or a stalklike projection
References in periodicals archive ?
At surgery, multiple colonic polyps were also noted.
7 Diverticulae 10 14 Internal Hemorrhoids 13 19 Colonic Polyps 13 27 Colonic Cancer 0 0 Normal 2 0 Other 5 0 Preparation Quality Good 20 23 Fair 6 1 Poor 0 2 Unknown 2 2 Variable p-Value Age (yr) 0.
However, the researchers believe the data suggest skin tags may hep identify persons at risk for colonic polyps and, possibly, cancer of the colon.
Extensive testing with radiologists has demonstrated that the use of VeraLook improved reader sensitivity to all colonic polyps in a statistically significant manner - particularly for smaller, more easily missed polyps and pre-cancerous polyps which can develop into malignancies over time.
Despite this shortcoming, the results showed "signals" that a low-fat diet produced some benefits, including a trend toward a reduced number of invasive breast cancers, a bigger reduction in breast cancers among women who had the highest level of fat in their diet at baseline, and a reduction in the incidence of colonic polyps or adenomas, said Dr.
Several investigators have studied the benefit of the use of prone imaging in addition to supine imaging, and it has been shown to increase the sensitivity for detection of colonic polyps (Figure 3).
Researchers have found that family members of patients with some types of colonic polyps may be at increased risk for developing colon cancer.
CAD for virtual colonoscopy has been shown to be effective in the detection of colonic polyps and to have a positive effect on reader sensitivity.
SAN FRANCISCO -- A combined laparoscopic-endoscopic approach can be effective in treating difficult colonic polyps, Dr.
We decided to proceed with a colonoscopy to rule out proximal colonic polyps or malignancy.
6-8] Gloeckner et al[9] recently described a large cell lymphoma with a marginal zone growth pattern presenting as multiple colonic polyps, and Schmid et al[10] described 3 cases of colorectal MALTomas (2 low grade and 1 mixed low and high grade) presenting as solitary polyps.
Moreover, there is evidence that these drugs reduce the incidence of colonic polyps and cancer, he said.