Tubular adenoma

Description:

Tubular adenoma (polypiform adenoma) — the benign tumor which is to monoclonal derivatives of a modified epithelial cell. Small (less than 1 cm) tubular adenoma has insignificant risk of regeneration in cancer. The majority of colorectal crayfish arise from adenomatous polyps. Therefore progress in treatment and the prevention of a colon cancer in many respects is defined by timely diagnosis of adenomas.

Reasons of tubular adenoma:

The origin of tubular adenomas is unknown. Epidemiological researches show that excess of animal fat in a diet promotes emergence not only a colon cancer, ache adenomatous polyps. It is known also that in the countries with high cancer cases of a large intestine a lot of animal fat and few fruit, vegetables and other products containing food fibers use. Excessively caloric food also increases risk of display of colorectal tumors.
Adenomas reveal approximately at 5% of the inspected persons and find at any age including at small children. Colorectal polyps are extremely widespread and in the western countries are found on materials of openings more, than at 30% of people 60 years are more senior.
Tubular adenomas tend to growth in process of increase in age. By the sizes adenomas happen different — absolutely small from several millimeters to 1 cm, and sometimes reach 2 — 3 cm. Polyps can have a knife - sou and can be located on the wide basis (sedentary). The leg of adenoma depends on the tumor size; can be thin and have length of lo of 1 — 1,5 cm, but it is more often thicker and shorter (length of 0,3 — 0,5 cm). At leg torsion adenoma can nekrotizirovatsya and samoamputirovatsya. At achievement of considerable size it can become a bleeding point in case of an ulceration or cause the strengthened slime secretion, result in impassability or invagination.
The main reason for studying of polyps is connected with their possible malignant regeneration in cancer. It is known that more than 95% of kolorektapny crayfish arise from high-quality adenomatous polyps. The exception is made by the hyperplastic polyps, gamartoma, lymphoid follicles and inflammatory polyps which are not regenerating in malignant tumors.
The neoplastic polyps or adenomas capable to malignant regeneration, are classified according to MKB-10 of World Health Organization as tubular (tubular), trubchatovorsinchaty and fleecy adenomas. Tubular adenomas form from straight lines or the branching tubules of displazirovanny fabric; fleecy adenomas contain finger-shaped outgrowths of a displazirovanny epithelium. About 70% of the polyps deleted at a kolonoskopiya make adenomas. From 70% to 85% from them are classified as tubular adenomas (contain up to 25% of fleecy fabric), from 10 to 25% — trubchatovorsinchaty (contain 25 — 75% of fleecy fabric) and око¬ло 5% make fleecy tumors (contain from 75% to 100% of fleecy fabric).
Elements of a dysplasia are somewhat inherent in all adenomatous polyps. Distinguish low - and high-differentiated a dysplasia. Highly differentiated dysplasia is very similar to cancer of "in situ". About 5 — 7% of patients with adenoma have high degree of a dysplasia, at 3 — 5% cancer of "in situ" comes to light. Degree of a dysplasia increases in process of increase in a share of fleecy fabric and age of patients. Frequency of cancer of "in situ" increases in process of increase in the sizes of an adenomatous polyp.
Most often single adenomas meet. On some site of a large intestine dense formation of rounded shape, smooth, without ulcerations, usually having a leg is located (but sometimes sitting on the wide basis). The mucous membrane covering adenoma as well as in general the mucous membrane of a large intestine is, as a rule, not changed has pink color and the normal vascular drawing.
Multiple adenomas, as a rule, of the small size (at most 0,5 cm in the diameter) and usually have absolutely short leg. The mucous membrane on other extent of a gut is not changed. Sometimes all mucous membrane of a colon is covered with adenomas of various form and size in such quantity that the site of a healthy mucous membrane is not even visible.

Symptoms of tubular adenoma:

The majority of polyps — the asymptomatic educations found accidentally during diagnostic testings. The most characteristic symptom of adenoma — bleeding. It is shown in the form of a blood strip (light and scarlet) on a surface a calla. Function of intestines at adenoma if there are no other diseases, is not broken. Only sometimes when adenoma reaches the big sizes, locks or ponosa can appear.

Diagnosis:

Rectal polyps reveal Kolo at endoscopy and X-ray inspection. Accuracy of diagnosis of polyps at a kolonoskopiya and an irrigoskopiya reaches respectively 94% to 67%. At an irrigoskopiya 52% of polyps by the sizes to 1 cm are baked thoroughly.
Undoubted advantage of a kolonoskopiya is an opportunity to carry out a biopsy and electrothermic coagulation of a polyp. It is necessary because in each case of detection of adenoma first of all it is necessary to exclude a possibility of its malignancy. Removal of adenomatous polyps prevents a colorectal cancer.
Despite the specified advantages, the kolonoskopiya also has restrictions at survey of some departments of a colon. Areas of splenic and hepatic bends, especially in the presence of acute angles concern to them. Quite often there are difficulties of visualization of the ileocecal valve. Besides, at 5 — 10% of the patients who especially underwent operations on pelvic bodies it is not possible to carry out the tool to a caecum.
It is also necessary to note that most of patients with the polyps found at a rektoromanoskopiya and X-ray inspection kolonoskopiya have to be exposed to exclude additional new growths. In cases when the size of a polyp is less than 1 cm, the decision has to be individual. It depends age of the patient, heredity and the anamnesis, in particular, of existence of colorectal polyps in the past. Kolonoskopiya has to be made before each polypectomy to find all synchronous adenomas. Frequency of synchronous adenomas at patients with single adenomas fluctuates according to different authors from 30 to 50%.

Differential diagnosis:

The diseases of a stomach, liver, pancreas which are quite often accompanying adenomas of a large intestine shade even those insignificant symptoms which accompany adenoma. Considering all this, it is important to conduct at any disease of digestive tract proctologic examination with a rektoromanoskopiya. Within availability of a rektoromanoskop there are about 2/3 adenomas of a large intestine. This circumstance emphasizes importance of dispensary inspections for the purpose of active detection of diseases of a large intestine.
Rektoromanoskopiya demands thorough training — the calla only in some sites can lead existence to the fact that adenoma will not be found.
Adenomas as true polyps, it is necessary to differentiate from hyperplastic, inflammatory polyps (pseudopolypuses) and fibrous polyps.
Hyperplastic polyps neozlokachestvlyatsya. Inflammatory polyps consist of granulyatsionny fabric, arise at ulcer colitis and other inflammatory diseases of a large intestine. Pseudopolypuses have the irregular cylindrical or rounded form, easily bleed, have no leg, are located against the background of the inflamed mucous membrane.
the fibrous polyp consists generally of connecting fabric and can have a leg.

Treatment of tubular adenoma:

Treatment of adenomas has to be only surgical. There are two methods of removal them: excision and electrothermic coagulation with an obligatory histologic research of a remote tumor.
The majority of polyps can be removed with the electrocoagulative equipment completely. Surgical bowel resection is carried out only in cases when there is obviously malignant polyp. The majority of the polyps having a leg are exposed to a histologic research entirely after removal. In this case the polyp can be correctly classified and presence or lack of a malignancy is completely proved.
Big sedentary polyps usually are removed in parts. In these cases it is more difficult to conduct a full histologic research of a polyp. In order that more considerably it was also convenient to remove a similar polyp, Shirai M. and соавт. (1994) previously enter saline solution into a submucosa.
The method of electrothermic coagulation is not recommended to be applied during removal of the adenomas located in the anal channel as anatomic conditions of this area prevent healing of the remaining burn surface. Therefore removal of adenomas of this localization is carried out by excision.
Electrothermic coagulation needs to be carried out so that adenoma was removed completely, and further there was no recurrence. On the other hand, electrothermic coagulation has to touch only a mucous membrane. Damage of deeper layers can lead to perforation of a wall with formation of abscesses in a basin, a paraproctitis and even peritonitis. It is necessary to be afraid of bleeding also.
It is necessary to emphasize that adenomas cannot be deleted by simple twisting at all. This method is not radical, and the most important can lead to dangerous profuse bleeding.
Electrothermic coagulation of adenomas is made during a kolonoskopiya.
After removal of adenoma there is a burn surface about 1 cm in size.
The endoscopic polypectomy reduces the frequency of a colon cancer by 50 — 79%. Winawer S.J. (1993) tracked 1418 patients who underwent a kolonoskopiya with removal at least of one adenomatous polyp. For the next 5 years the frequency of developing of cancer at them was 76 — 90% lower, than in group of control.
Perforation and bleeding complicate an endoscopic polypectomy approximately in 0,2% and 1% of cases, respectively.

Forecast:

After excision of a big sedentary polyp (more than 2 cm), the control kolonoskopiya is usually carried out in 3 — 6 months. If find the polyp remains, then again excise it and control completeness of a resection through the following of 3 — 6 months. If the full resection does not manage to be carried out after two or three electrothermic coagulations, then the patient should offer surgical treatment.
The subsequent control endoscopic researches have to be conducted at least 1 time a year.