Benign tumors of the colon

Definition

Benign tumors of the large intestine are neoplasms localized in different parts of the colon, originating from different layers of the intestinal wall and not prone to metastasis. Symptoms of this group of diseases are periodic pain along the course of the large intestine, minor bleeding from the anus, and stool disorders. Colonoscopy, lower gastrointestinal series, sigmoidoscopy, finger examination of the rectum, stool analysis for hidden blood, and a general blood test are used to diagnose benign large intestine tumors. Treatment of benign tumors consists of their removal by endoscopy or by resection of the intestine.

General information

Benign tumors of the large intestine are different in structure. They usually grow in the intestinal lumen and do not metastasize to other organs. They are often represented by adenomatous polyps, which develop from epithelial tissue. Lipomas, angiomas, fibromas, leiomyomas, and other non-epithelial tumors are detected less often. These formations are predominantly found in people over 50 years of age.

Some hereditary forms of the disease can be detected in children and remain asymptomatic for a long time. These include, for example, familial polyposis of the colon. The danger of this pathology is that, over time, it can be transformed into cancer, which is due to the loss of the ability of tumor cells to differentiate. The study of benign tumors of colorectal localization is engaged in proctology and oncology. This pathology is diagnosed and treated by proctologists, oncologists, gastroenterologists, and abdominal surgeons.

Causes

The causes of benign colorectal tumors are not definitively understood. One of the most important factors that play a significant role in the development of intestinal neoplasms is considered to be heredity: if relatives have intestinal polyps, the risk of developing a benign colon tumor increases.

This pathological process can develop against the background of excessive consumption of fatty foods and insufficient introduction of foods containing fiber into the diet. The risk of benign neoplasia of the colon is increased in people with frequent and prolonged constipation. Often, the disease develops against the background of nonspecific ulcerative colitis, chronic inflammation of the large intestine, and Crohn’s disease. Risk factors also include a long history of smoking, low physical activity, and age over 50 years.

Classification

Benign tumors of the large intestine include lipomas, leiomyomas, lymphangiomas, neurinomas, fibromas, hemangiomas, adenomatous polyps, and villous tumors. Familial colorectal polyposis and carcinoid tumors also fall into this category.

• Adenomatous polyps are the most common benign neoplasms that develop from epithelial tissue.
• Lipoma is the most common benign tumor of non-epithelial origin. In terms of prevalence, it is only slightly inferior to polyps. Lipoma differs from other neoplasms by its soft consistency.
• Fibroma is a relatively rare tumor of the large intestine that develops from connective tissue and occurs predominantly in the elderly.
• Leiomyoma originates from smooth muscle fibers and is a rare neoplasm. Neurinoma is characterized by small size and growth inside the mucosa and serosa.
• Hemangioma develops from the vascular tissue of the large intestine and is located closer to the border of the rectum. This benign tumor is most often manifested by intestinal bleeding.

Symptoms of benign colon tumors

The clinical symptomatology of benign tumors of the large intestine depends on their size. Small neoplasms may not manifest themselves in any way and are often detected only during endoscopy. Therefore, in most cases, such benign large intestine tumors are almost asymptomatic. When the neoplasm is larger than 2 cm, it is manifested by bloody discharge during defecation and other symptoms that depend on the structure and localization of the process.

In addition, benign tumors are accompanied by abdominal pain of varying intensity. The pain may have both a nagging and a contraction-like character. As a rule, it increases before defecation and subsides after emptying the bowel.

In benign tumors, stool disorders such as diarrhea or constipation may occur. If the patient has bleeding from the tumor, symptoms of anemia such as weakness, pallor of the skin, and decreased performance may occur. A distinctive feature of these neoplasms from malignant is the absence of symptoms of tumor intoxication: weight loss, profuse sweating, fatigue, and loss of appetite.

Complications

Diffuse polyposis of the colon is often accompanied by periodic intestinal bleeding, which resembles the symptoms of hemorrhoids. Bloody discharge usually occurs after cramping-like pain in the lower half of the abdomen or defecation. Most often, bleeding is observed when polyps are localized in the area of the sigmoid and rectum. Large benign polyps can lead to complete or partial intestinal obstruction, which is a severe complication.

Diagnosis

Laboratory and instrumental research methods are used to diagnose benign large intestine tumors. The examination data of a proctologist are, in most cases, uninformative. In some cases, pallor of the skin and the presence of bloody discharge from the anus may be noted.

• Laboratory studies. A general blood test is used, in which a decrease in the level of red blood cells and hemoglobin is noted in the presence of bleeding. Signs of anemia are most often observed with multiple bleeding polyps of the colon. Minor bleeding is diagnosed and on examination when a fecal occult blood test is conducted.
• Lower gastrointestinal series. A contrast containing barium is injected to better visualize the intestine. This study detects mucosal filling defects, which indicate the presence of a tumor. The radiological criterion of benign tumors of the large intestine is the presence of a mobile filling defect with smooth, even, and clear edges without changes in the relief of the mucosa. 
• Endoscopy of the intestine. An important method of diagnosing benign tumors is endoscopy of various parts of the large intestine. Sigmoidoscopy examines the rectum and the lower parts of the large intestine. Colonoscopy makes it possible to examine the entire intestine for benign tumors. During this diagnostic procedure, the proctologist can take tissue samples for morphological examination, which will make it possible to clarify the morphology of the tumor and determine the treatment tactics.

In most cases (60-75%), benign tumors of the large intestine are well visualized with a rectoscope or colonoscope. Polyps may be located either on a thin pedicle or on a broad base. The mucosa of benign tumors of the large intestine typically has a pink color, although in some cases, it may be purplish-red, standing out against the surrounding tissue. A mucosal defect with edematous edges covered with fibrinous plaque is visualized in case of erosions.

Treatment of intestinal tumors

Surgical methods are used for treatment, which involves the removal of neoplasms. Pharmacotherapy in this group of diseases is considered ineffective. Polyposis of any localization is a precancerous pathology, so it is recommended to be eliminated promptly. Single polyps are removed by endoscopic electrocoagulation or resection of the colon. In severe multiple polyposis with a high risk of cancer development, radical removal of the colon – colectomy – may be recommended. After such surgical interventions, reconstructive colorectal surgeries are performed to restore normal bowel function.

Treatment tactics for other types of benign tumors of the large intestine are determined by the type of neoplasm, its size, and the presence or absence of complications. To eliminate single benign neoplasia, colonoscopy with endoscopic removal of the formation is used today. This method is applicable in the presence of a solitary tumor node with a pronounced pedicle. Endoscopic removal is well tolerated by patients, who fully recover the next day and can return to their usual way of life.

The removed neoplasm is necessarily sent for histological examination, which can clarify the tumor’s morphology and ensure that it does not contain malignant cells. In some cases, surgical treatment is performed by performing organ-preserving or radical operations. 

After removing large benign tumors, a control endoscopy is recommended after a year to ensure that new polyps are not missed. If neoplasms arise at the site of the removed tumor again, they must necessarily be removed again. The following diagnostic procedure is carried out after three years without new polyps on the control colonoscopy.

All these treatment options are available in more than 700 hospitals worldwide (https://doctor.global/results/diseases/benign-tumors-of-the-colon). For example, Colorectal endoscopic mucosal resection (EMR) can be performed in 44 clinics across Germany for an approximate price of $5,8K (https://doctor.global/results/europe/germany/all-cities/all-specializations/procedures/colorectal-endoscopic-mucosal-resection-emr). 

Prognosis and prevention

With proper and timely removal of benign tumors of the large intestine, this group of diseases has a favorable prognosis. However, if the polyp develops into a malignant tumor, the disease can lead to a fatal outcome. After removal of benign neoplasm for timely detection of recurrences, repeat sigmoidoscopy, lower gastrointestinal series, or colonoscopy is performed.