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Benign tumors of a large intestine

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Benign tumors of a large intestine
Histologic structure of a polyp

The benign tumors developing from ferruterous fabric are called adenomas, or adenomatous (ferruterous) polyps. According to V.D. Fedorov et al. (1984), they make 90-92% of all benign tumors of a large intestine.

In most cases clinically polyps proceed asymptomatically, and only large adenomas can be shown by release of blood or slime at the act of defecation.
Relative frequency of adenomas, and also the concept about their leading role in development of a colon cancer do a problem of diagnosis of benign epithelial tumors of one of main for endoscopists. Kolonoskopiya as the most exact method of detection of polyps, allows to estimate also objectively a number of the parameters having great clinical value. Treat them:

  1. anatomic type of a polyp;
  2. polyp sizes;
  3. histologic structure of a polyp;
  4. quantity of polyps.

Anatomic type and sizes of a polyp

On the basis of the macroscopic characteristic of polyps which main criteria are the education basis width, its height, diameter, and also the area of damage of a mucous membrane allocate five anatomic types of adenomas (Rubio C. And. et al., 2002; Kashida H., Kudo S., 2003):

  1. Pediculated polype — a tumor with well differentiated leg which can be short (leg length no more than 1 cm) or long (leg length more than 1 cm), a conical or cylindrical shape. The polyp top in most cases has the large sizes (from 1-1,5 to 3-4 cm and more in the diameter), a myagkoelastichesky consistence, a surface its rough or lobular (the scheme, a).
  2. Polyp on the narrow basis — a tumor with accurately expressed neck which diameter is less than the widest part of a polyp, its sizes — about 1 cm, a surface either smooth, or rough or melkodolchaty, a consistence soft or myagkoelastichesky. At capture of a biopsy elasticity of fabrics of education is kept, moderate bleeding is noted them, (the scheme, b).
  3. Polyp on the wide basis, or a "sedentary" polyp — a tumor of a soft consistence, the small sizes (from 2-3 mm to 7-10 mm), with a smooth plain surface. At the same time width of the basis is more than height no more than twice. Color of adenomas to 5 mm in the diameter, as a rule, does not differ from color of a surrounding mucous membrane. Polyps of the big sizes have more intensive coloring, and the surface gets them the rough or poorly expressed lobular character (the scheme, c).
  4. Flat adenoma — a tumor of a rounded or oval shape, the small sizes (to 4-6 mm in the diameter), no more than 1-2 mm high, a softish or myagkoelastichesky consistence. The surface its smooth or fine-grained, on color practically does not differ from a surrounding mucous membrane. The majority of adenomas of this type in the center has an impression without clear boundary (Kudo S., 1996; Fujii T. et al., 1998; Muto T., 1998; O'Brien M. et al., 2001). At capture of a biopsy moderate bleeding is noted (the scheme, d).
  5. The growing adenoma flat longwise (laterally spreading tumor, LST-adenoma) — the flat tumor affecting the big area of a mucous membrane of a large intestine. At the same time its longitudinal sizes always much more exceed cross (the scheme 27, e). Length longwise of the growing adenomas varies from 3-5 to 15 cm and more, height — from several millimeters to 1-1,5 cm. The surface of a tumor can be rough, hilly or fine-grained, color light pink or brighter in comparison with a surrounding mucous membrane (Kudo S., 1996; Raju G.S., Pasricha P.J., 2003). At capture of a biopsy the increased fragility and the expressed bleeding of fabrics of education is noted.

типы полипов толстой кишки
Scheme. Anatomic types of polyps of a large intestine
and. Pediculated polype.
. A polyp on the narrow basis.
century.  A polyp on the wide basis (a "sedentary" polyp).
.  A flat polyp with the central impression.
  of LST adenoma (the growing adenomas flat longwise).

The concept of staging of development of neoplastic process according to which the risk of malignant transformation of polyps increases with increase in their sizes, explains importance of an assessment and this indicator (Aruin L.I. et al., 1998; Veselov V. V., Kuzmin A.I., 2002; Hamilton S.R., 1992).
It is conditional all high-quality epithelial formations of a large intestine are subdivided into the small, small, average and large.
Polyps which diameter makes several millimeters (1-5 mm), small — polyps which sizes do not exceed 1 cm in the diameter (5-10 mm), averages — adenomas with a diameter from 1 to 2,5 cm, large — educations which amount exceeds 2,5-3,0 cm (Tedesco F are considered as smallest (diminutive polyps). J. et al., 1982; Goldstein N. S. et al., 2001). At an assessment of the sizes of flat adenomas and the growing tumors flat longwise the area of damage of a mucous membrane is considered. At small flat polyps the area of damage of a mucous membrane, as a rule, does not exceed 1 cm, at average the growing tumors flat longwise — to 3-4 cm. Tumors up to 6 cm, huge - the area of which of more than 6 cm are considered as the growing tumors large longwise (Strekalovsky V.P. et al., 1986, 1989; Morita T. et al., 2001).
According to most of authors it is established that the most widespread benign epithelial tumors in a large intestine are small adenomas of the 1st and 3rd type.

About 80% fall to their share. Large epithelial educations meet seldom, they make only 2,5-3% (Veselov V. V., 1997; Winawer S.J. et al., 1993, 2003).



 
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