villous adenoma


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Related to villous adenoma: tubular adenoma

adenoma

 [ad″ĕ-no´mah]
a benign epithelial tumor in which the cells form recognizable glandular structures or in which the cells are derived from glandular epithelium.
acidophilic adenoma in a classification system formerly used for pituitary adenomas, an adenoma whose cells stain pale pink with acid dyes; most adenomas that secreted excessive amounts of growth hormone were in this group
ACTH-secreting adenoma (adrenocorticotrophic hormone–secreting adenoma) corticotroph adenoma.
basophilic adenoma in a classification system formerly used for pituitary adenomas, an adenoma whose cells stain pale blue with basic dyes; most adenomas that secreted excessive amounts of adrenocorticotrophic hormone were in this group.
chromophobe adenoma (chromophobic adenoma) a pituitary adenoma composed of cells that lack acidophilic or basophilic granules; this is the same entity as the more precisely named null-cell a.
corticotrope adenoma (corticotroph adenoma) a pituitary adenoma made up predominantly of corticotrophs; excessive corticotropin secretion may cause Cushing's disease or Nelson's syndrome. Called also ACTH-secreting or adrenocorticotropic hormone–secreting adenoma and corticotropinoma.
endocrine-active adenoma a pituitary adenoma that secretes excessive amounts of a hormone; see prolactinoma, corticotroph adenoma, gonadotroph adenoma, growth hormone–secreting adenoma, and thyrotroph adenoma. Called also hyperfunctional or hyperfunctioning adenoma.
endocrine-inactive adenoma a pituitary adenoma that does not secrete excessive amounts of any hormone; many null-cell adenomas are of this type. Called also nonfunctional or nonfunctioning adenoma and nonsecreting or nonsecretory adenoma.
gonadotrope adenoma (gonadotroph adenoma) a rare type of pituitary adenoma made up of gonadotroph-like cells that secrete excessive amounts of follicle-stimulating hormone or luteinizing hormone or both; it may cause precocious puberty, visual disturbances, or hypogonadism.
growth hormone–secreting adenoma a pituitary adenoma made up of somatotroph-like cells that secrete excessive amounts of growth hormone; it may cause gigantism in children or acromegaly in adults. Called also somatotrope or somatotroph adenoma and eosinophilic adenoma.
hepatocellular adenoma a large, fleshy, hypervascular tumor of the liver occurring chiefly in women of childbearing age and associated with oral contraceptive use. It is composed of sheets of cells with areas of hemorrhage and necrosis and has a tendency to hemorrhage and rupture; it may become malignant.
Hürthle cell adenoma a benign hürthle cell tumor.
hyperfunctional adenoma (hyperfunctioning adenoma) endocrine-active adenoma.
lactotrope adenoma (lactotroph adenoma) prolactinoma.
liver cell adenoma hepatocellular adenoma.
nonfunctional adenoma (nonfunctioning adenoma) endocrine-inactive adenoma.
nonsecreting adenoma (nonsecretory adenoma) endocrine-inactive adenoma.
null-cell adenoma a pituitary adenoma whose cells give negative results on tests for staining and hormone secretion; although classically they were considered to be composed of sparsely granulated or degranulated (nonfunctioning) cells, some contain functioning cells and may be associated with a hyperpituitary state such as acromegaly or Cushing's syndrome. These tumors are often discovered clinically only when they have grown large and are pressing on surrounding structures. Called also chromophobic adenoma.
pituitary adenoma a benign neoplasm of the anterior pituitary gland; some contain hormone-secreting cells (endocrine-active adenomas) but some are not secretory (endocrine-inactive adenomas).
plurihormonal adenoma an endocrine-active adenoma that secretes more than one kind of hormone.
prolactin cell adenoma (prolactin-secreting adenoma) prolactinoma.
sebaceous adenoma hypertrophy or benign hyperplasia of a sebaceous (oil-secreting) gland.
adenoma seba´ceum nevoid hyperplasia of sebaceous glands, forming multiple yellow papules or nodules on the face. See also nevus.
somatotrope adenoma (somatotroph adenoma) growth hormone–secreting adenoma.
thyroid-stimulating hormone–secreting adenoma thyrotroph adenoma.
thyrotrope adenoma (thyrotroph adenoma) (TSH-secreting adenoma) a rare type of pituitary adenoma made up of thyrotroph-like cells that secrete excess thyrotropin and cause hyperthyroidism; called also thyroid stimulating hormone–secreting adenoma.
villous adenoma a large soft papillary polyp on the mucosa of the large intestine.

vil·lous ad·e·no·ma

frequently appears as a solitary, sessile, often large, tumor of colonic mucosa, although it can occur anywhere through the GI tract; composed of mucinous epithelium covering delicate vascular projections; malignant change occurs frequently; hypersecretion occurs rarely. Also known as adenoma.

villous adenoma

n.
A usually solitary, often large sessile tumor of the mucosa of the large intestine, composed of mucinous epithelium covering delicate vascular projections.

villous adenoma

[vil′əs]
Etymology: L, villus, hair
a slow-growing, soft, spongy, potentially malignant papillary growth of the mucosa of the large intestine.
enlarge picture
Villous adenoma: endoscopic view

vil·lous ad·e·no·ma

(vil'ŭs ad'ĕ-nō'mă)
A solitary sessile, often large, tumor of colonic mucosa composed of mucinous epithelium covering delicate vascular projections; malignant change occurs frequently.
Synonym(s): papillary adenoma of large intestine.

villous adenoma

A benign, finger-like tumour of the COLON that often secretes excessive quantities of mucus and may develop into a cancer.
References in periodicals archive ?
Prognosis is excellent for patients with isolated villous adenoma, with rarely ever any recurrence after transurethral resection.
Villous adenoma of the urinary bladder is a rare but important lesion.
Villous adenoma of the urinary tract: a report of 23 cases, including 8 with coexistent adenocarcinoma.
Villous adenoma of the urinary tract: a lesion frequently associated with malignancy.
Concurrence of villous adenoma and non-muscle invasive bladder cancer arising in the bladder: a case report and review of the literature.
A case of villous adenoma of the urinary bladder with tubulovillous architecture: characterization by immunohistochemical analysis.
While locally recurrent and metastatic adenocarcinomas have not been observed in association with villous adenoma of the renal pelvis, this type of aggressive behaviour has been observed in the bladder.
Given its rarity, there are no guidelines for follow-up or adjuvant treatment of intestinal-type villous adenoma in the renal pelvis following resection.
Intestinal type villous adenoma of the renal pelvis is challenging to diagnose prior to surgical resection but symptoms such as mucosuria, dysuria, flank and abdominal pain, as well as a history of recurrent urinary tract infections and urolithiasis, may be present.
Mucinous adenocarcinoma with superficial stromal invasion and villous adenoma of urachal remnants: a case report.
Villous Adenoma in the Native Kidney of a Renal Transplant Recipient.
3] We feel that these lesions differ from classic tubular and villous adenomas in 2 principal respects: first, the proliferative activity, as demonstrated by Ki-67 staining, is seen throughout the lesions but predominantly at the base of crypts rather than the surface.