polyp

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

polyp

[pol´ip] any growth or mass protruding from a mucous membrane. Polyps may be attached to a membrane by a thin stalk (pedunculated polyps), or they may have a broad base (sessile polyps). They are usually an overgrowth of normal tissue, but sometimes they are true tumors (masses of new tissue separate from the supporting membrane). Usually benign, they may lead to complications or eventually become malignant. They can occur wherever there is mucous membrane: in the nose, ears, mouth, lungs, heart, stomach, intestines, urinary bladder, uterus, and cervix.intestinal p's polyps in the intestines, usually found in middle age although some infants are born with them in the large intestine. Multiple intestinal polyps may be a hereditary disorder. In most cases they cause no symptoms unless they become large enough to obstruct the intestine or become ulcerated so that they bleed. When they do, symptoms may include cramping pains in the lower abdomen, diarrhea, and the passage of blood and mucus. Whether or not they cause symptoms, intestinal polyps should be removed, since any one of them may become malignant. Although all causes of intestinal cancer have not yet been discovered, it is believed that polyps are often a contributing factor.nasal p's polyps in the nasal cavity or sinuses, usually produced by local irritation, sometimes as a result of an allergy. They are not dangerous, but if they grow large enough to extend into the nose, they may cause stuffiness and headaches. The allergy or other source of irritation responsible for the polyps should be treated; if the polyps continue to be troublesome, surgery may be necessary.

pol·yp

(pol'ip), A general descriptive term used with reference to any mass of tissue that bulges or projects outward or upward from the normal surface level, thereby being macroscopically visible as a hemispheroidal, spheroidal, or irregular moundlike structure growing from a relatively broad base or a slender stalk; polyps may be neoplasms, foci of inflammation, degenerative lesions, or malformations. Synonym(s): polypus [L. polypus; G. polypous, contr. fr. G. polys, many, + pous, foot]

polyp

(pŏl′ĭp)n. A usually nonmalignant growth or tumor protruding from the mucous lining of an organ such as the nose, bladder, or intestine, sometimes causing obstruction.

pol′yp·oid′ adj.

polyp

An elevated 'tumor' mass, which is usually epithelial, and often neoplastic; polyps are common in the colon, ♀ genital tract, nasopharynx, stomach See Bladder polyp, Cervical polyp, Colon polyp, Hairy polyp, Inflammatory polyp, Inflammatory fibroid polyp, Juvenile polyp, Pseudopolyp, Retention polyp. Polyps Colon Colonic polyps are usually epithelial, and are acquired or hereditary Acquired polyps Adenomatous (tubular or villous) in morphology, ↑ frequency with age; although often asymptomatic, larger polyps are often announced by bleeding, or changed bowel habits; if really large, APs may form a leading 'front' of an intussusception; distinction between adenomatous polyps ('tight' round glands) and villous adenomas (finger-like fronds of elongated glands) has little practical importance–both have malignant potential; periodic colonoscopy and polypectomy yields a 3-fold ↓ in subsequent cancer; hyperplastic polyps are also acquired but are non-neoplastic Hereditary polyps are epithelial and may overlap with each other • Familial adenomatous polyposis (FAP) A premalignant, AD MIM 175100 condition presenting in early adulthood with 100s to 1000s of colonic polyps, related to a loss of the normal repression of DNA synthesis in the entire colonic epithelium; adenocarcinoma occurs in 70–100% of Pts, prevented by prophylactic colectomy • Gardner syndrome A rare AD MIM 175100 condition with premalignant polyps of the entire GI tract, which is identical to FAP, but has, in addition, extraintestinal tumors; most Pts develop colon carcinoma; other neoplasms in GS Pts include bile duct carcinoma, osteomas of the mandible, skull, and long bones, soft tissue tumors (fibromas, lipomas), sebaceous cysts, and rarely, thyroid and adrenal gland cancers • Turcott syndrome A rare AR MIM 276300 condition associated with brain tumors, eg medulloblastoma, glioblastoma • Other colon polyps Hamartomas, hyperplastic polyps, juvenile and retention polyps–little neoplastic potential • Turcott syndrome A non-hereditary condition characterized by diffuse GI polyposis, accompanied by alopecia, nail atrophy, cutaneous hyperpigmentation, weight loss, protein-losing enteropathy, electrolyte imbalance and malnutrition • Peutz-Jeghers syndrome An AD MIM 175200 condition with hamartomas of the entire GI tract, predominantly of the small intestine, focal Paneth cell hyperplasia, melanin spots in buccal mucosa, lips, and digits, intussusception and bleeding; colonic adenocarcinomas, when seen in PJS, arise in adenomatous and not in hamartomatous polyps; PJS may be associated with Sertoli cell tumor with annular tubules, see SCTAT. Female urogenital tract Endometrial and endocervical polyps are circumscribed foci of cystic glandular hyperplasia of the mucosa and may cause abnormal bleeding; carcinoma arising in such polyps is rare; when smooth muscle is also present, they are designated as adenomatous polyps DiffDx Polypoid smooth muscle tumors, benign and malignant. See Müllerian mixed tumor. Nasopharynx Nasal polyps Inflammatory ('allergic') polyps of the nasal cavity are not neoplastic, but rather reactive to inflammation or allergy; unlike true polyps, nasal polyps display edema and chronic inflammation (eosinophils, plasma cells, and lymphocytes), are bilateral, recurrent, and intranasal Skin Squamous polyps and fibroepithelial polyps or 'skin tags' are benign prolapses of upper dermis onto the skin surface, which have no neoplastic potential Stomach polyp Gastric polyp It is often (incorrectly) assumed that colon polyps are analogous to gastric polyps; hyperplastic polyps (type I and II polyps by Japanese authors) comprise 75% of all gastric polyps; they are neoplastic, but are usually benign

pol·yp

(pol'ip) A general descriptive term used with reference to any mass of tissue that bulges or projects outward or upward from the normal surface level, thereby being macroscopically visible as a hemispheroid, spheroid, or irregular moundlike structure growing from a relatively broad base or a slender stalk; polyps may be neoplasms, foci of inflammation, degenerative lesions, or malformations.
Synonym(s): polypus. [L. polypus; G. polypous, contr. fr. G. polys, many, + pous, foot]

polyp

(pol'ip) [Gr. polypous, many-footed, octopus, nasal tumor] A swelling or excrescence (tumor) emanating from a mucous membrane; commonly found in vascular organs such as the nose, uterus, colon, and rectum. Polyps bleed easily; if there is a possibility that they will become malignant, they should be removed surgically. Synonym: polypus

adenomatous polyp

Benign neoplastic tissue originating in the glandular epithelium.

antrochoanal polyp

A nasal polyp found near the posterior wall of the maxillary sinus.

aural polyp

Polypoid granulation tissue in the external canal of the ear attached to the tympanic membrane or middle ear structures.

bleeding polyp

An angioma of the nasal mucous membrane.

cardiac polyp

A pedunculated tumor attached to the inside of the heart. If situated close to a valve, it may cause blockage of the valve intermittently.

cervical polyp

A usually benign growth of the cervical mucosa.

choanal polyp

A nasal polyp that extends into the pharynx.

POLYPS: Polyps in the colon, seen endoscopically

colonic polyp

An abnormal tissue growth within the lumen of the colon. It may be benign or malignant. See: illustration

fibrinous polyp

A polyp containing fibrin and blood, located in the uterine cavity.

fibroepithelial polyp

A smooth-surfaced polyp of the oral mucosa, usually developing after trauma to the area. See: acrochordon

fleshy polyp

A submucous myoma in the uterus, consisting of benign neoplastic tissue from smooth muscle.

gelatinous polyp

1. A polyp made up of loose swollen edematous tissue.2. A myxoma.

Hopmann polyp

See: Hopmann, Carl Melchior

hydatid polyp

A cystic polyp.

juvenile polyp

A benign rounded mucosal hamartoma of the large bowel. This type of polyp may be present in large numbers in infants and is commonly associated with rectal bleeding. Synonym: retention polyp

laryngeal polyp

A polyp attached to the vocal cords and extending to the air passageway.

lymphoid polyp

A benign lymphoma of the rectum.

mucous polyp

A polyp of soft or jelly-like consistency and exhibiting mucoid degeneration.

NASAL POLYPS

nasal polyp

A pedunculated polyp of the nasal mucosa. See: illustration

Nasal polyps are the most commonly identified nonmalignant tumor of the nasal passages. They are more commonly identified in men than in women.

Symptoms

The most common symptom of nasal polyposis is obstruction to the flow of air into and out of the nasal passages.

Treatment

Steroid nasal sprays may improve airflow through the nasal passages. Surgical removal of polyps may occasionally be necessary when medical treatment is unsuccessful.

placental polyp

A polyp composed of retained placental tissue.

retention polyp

Juvenile polyp.

vascular polyp

A pedunculated angioma.

polyp

Any growth or mass of tissue projecting, usually on a stalk, from a surface, especially a mucous membrane. Polyps commonly occur on the lining of the nose, the LARYNX, the intestine and the cervix of the womb. Most polyps are BENIGN but some become MALIGNANT. Surgical removal is generally easy.

polyp

the asexually reproducing, normally sedentary form of COELENTERATES such as the sea anemone (see MEDUSA). In the class Anthozoa the polyp stage is the dominant part of the life history, but in the Scyphozoa (jellyfish) it is often absent.

Polyp

A lump of tissue protruding from the lining of an organ, such as the nose, bladder, or intestine. Polyps can sometimes block the passages in which they are found.Mentioned in: Aspirin, Bowel Preparation, Corticosteroids, Inhaled, Hysteroscopy, Hysterosonography, Nasal Papillomas, Sigmoidoscopy, Smelling Disorders, Stomach Cancer

pol·yp

(pol'ip) General descriptive term used with reference to any mass of tissue that bulges or projects outward or upward from normal surface level; may be neoplasms, foci of inflammation, degenerative lesions, or malformations. [L. polypus; G. polypous, contr. fr. G. polys, many, + pous, foot]

Patient discussion about polyp

Q. Blood in stools before and after polyp removel, Avms of the deodenel loop, inside hems, and 3cin tubuo adenoma Hi, On Nov of 06 I had a colonoscopy done and they didnt find any thing that could be mking me bleed and go to the rest room often. Then in Nov of 07 did a EDg and found I have AVMs of the deodenel loop.She Burned them and I didnt have any more bleeding till June of thei yr.On 6/6/08 i had another EDg done she burned more AVMs and on Mon I started bleeding again. This time she did a colonoscopy and found I had inside hems and a 3cin tubuolvillous adenoma inflamed.She cut, burned, and took it out in peices.She saye she will go back in Nov of this yr and look again. Two weeks after I had this done I had started to bleed again and had bad such bad pain in my hip I had to hold on to walk. that same day i started to bleed again. I bled out big clots and a bowl full of blood! A few days later the pain went away but was still bleeding ever time I had bowl movement!I can bleed up to 4 days at a times sometimes. I have been taking HC supp. and it seems to have stoped the bleeding and pain! A. It is normal that after a polyp removal you will continue bleeding some more. However, if you feel like there is a lot of bleeding, and/or you are not feeling well, you should see a doctor as soon as possible to stop the bleeding or look for the source of bleeding.

More discussions about polyp

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polyp,

Polyp

Polyp

REFERENCES

polyp

polyp

polyp

polyp

pol·yp

polyp

polyp

pol·yp

polyp

adenomatous polyp

antrochoanal polyp

aural polyp

bleeding polyp

cardiac polyp

cervical polyp

choanal polyp

colonic polyp

fibrinous polyp

fibroepithelial polyp

fleshy polyp

gelatinous polyp

Hopmann polyp

hydatid polyp

juvenile polyp

laryngeal polyp

lymphoid polyp

mucous polyp

nasal polyp

Symptoms

Treatment

placental polyp

retention polyp

vascular polyp

polyp

polyp

Polyp

pol·yp

Patient discussion about polyp

polyp

Synonyms for polyp

noun a small vascular growth on the surface of a mucous membrane

Synonyms

Related Words

noun one of two forms that coelenterates take (e.g. a hydra or coral): usually sedentary with a hollow cylindrical body usually with a ring of tentacles around the mouth

Related Words