ADENOMA (adenoma; Greek aden — gland + oma) — the benign tumor arising from a ferruterous epithelium. Macroscopically And. has an appearance of a polyp on a thin leg or on the wide basis (adenomatous polyp). More often And. it is presented by the node which is accurately outlined, delimited by the capsule located in the thickness of body. And. happen multiple. Microscopically And. has an organoid structure with well distinguishable epithelial parenchyma and a connective tissue stroma. An epithelium in And. it is located on own cover (membrana propria), keeps polarity, and it is frequent also ability to produce a secret, characteristic of this body — proteinaceous and mucous masses in And. sialadens, a colloid in And. a thyroid gland, neutral fat in And. sebaceous glands (fig. 1). Under the influence of the collecting secret or regardless of it in And. cystous cavities can be formed, in these cases the tumor is called a cystadenoma or an adenocystoma, and in the presence in a gleam of a cyst of papillary growths — a papillary cystadenoma. Depending on a form, character of an arrangement of ferruterous structures in And. and ratios of epithelial and connective tissue components histologically distinguish several types of A. V trabecular, or solid, And. (fig. 2) of a cell are grouped in the form of compact tyazhy, divided by very thin coat of a fibrous stroma. Tubular And. (fig. 3) is characterized by the narrow channels covered by a cubic or prismatic epithelium, usually find a secret in a gleam of channels. Alveolar (or acinous) And. develops at the expense of trailer departments of the branching glands. The ampere-second dominance of a fibrous stroma is called a fibroadenoma. Also the mixed structural options A meet., e.g. tubuloalveolar And. sialaden, etc.
And. can develop at any age, lokalizuyas in any body where there is a ferruterous epithelium (e.g., in a thyroid gland).
The originality of a structure of this or that body quite often receives reflection and in structure arising in it And., which, however, can arise also in other body (geterotopny And.). In a thyroid gland arise follicular And. according to a typical structure of body of a pla fetalis which picture reminds a structure of a thyroid gland at certain stages of pre-natal development. Besides, in thyroid, parathyroid, parotid salivary and some other glands meet so-called onkotsitarny And., or oncocytomas — tumors from rather large cells with wide oxyphilic cytoplasm. In a thyroid gland cellular elements of these new growths identify with Gyurtle's cells — Askanazi (see. Thyroid gland). Sometimes And. arise in the period of embryonic development — inborn And.
At microscopic examination sometimes there are difficulties in an otgranicheniya And. from reactive and compensatory and adaptive ferruterous giperplaziya. To a large extent it belongs to And. hemadens. And. have expansive (exophytic or endophytic) growth.
The majority of adenomas has high-quality character, and the clinical course of these tumors is defined by localization, growth rate and the size of a new growth (see articles about separate bodies). Part A. it is transformed to cancer. So, the adenocarcinoma of a large intestine is usually preceded by an adenomatous polyp. The papillary cystadenoma of ovaries quite often forms a basis for developing of papillary cancer. On the other hand, the fibroadenoma of a mammary gland only sometimes becomes a source of cancer or sarcoma of this body. Some malignant new growths having invasive growth differ in a weak structural atipizm and on this basis are designated by very conditional term «destruiruyushchy, or malignant, adenoma» though actually they are the high-differentiated ferruterous crayfish (malignant And. endometria).
The forecast at the majority And. favorable. Treatment, as a rule, surgical. Some And. and adenomatous polyps went. - kish. a path, apparently, have hereditary and family character. Prevention of some And. comes down to elimination of dishormonal disturbances.
See also Tumors .
Bibliography: Davydovsky I. V. General pathology of the person, page 530, M., 1969, bibliogr.; Strukov A. I. Pathological anatomy, page 215, M., 1971.
Yu. N. Solovyov.