Benign tumors of the small intestine
Last reviewed: 23.04.2024
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The international histological classification of intestinal tumors (WHO, No. 15, Geneva, 1981) identifies the following benign small bowel tumors:
- epithelial;
- carcinoid;
- non-epithelial tumors.
Epithelial tumors of the small intestine are represented by an adenoma. It has the appearance of a polyp on the pedicle or on a broad base and can be tubular (adenomatous polyp), villous and tubulovorsinous. Adenomas in the small intestine are rarely seen, most often in the duodenum. A combination of adenoma of the distal ileum with adenomatosis of the colon is possible.
Carcinoids occur in the crypt region of the mucosa and in the submucosa. The epithelial cover is initially preserved, and then often ulcerated. The carcinoid is of small size cells without clear boundaries with uniform rounded nuclei. Tumor cells form wide layers, strands and cells. Sometimes you can find a small number of acinar and "rosette" structures.
Carcinoids are divided into argentaffin and nonargentaffin. Argentaffin carcinoids are characterized by the presence in the cytoplasm of cells of eosinophil granules that are blackened by the argyentaffin reaction (the Fontana method) and brownish-red when diazomethane is used. Argentaffin, as well as chromaffin reactions (in the treatment with chromic acid or bichromate granules are colored brown) carcinoids are due to the presence of serotonin in them, in these cases the carcinoid is clinically expressed as a carcinoid syndrome. The nonargentaffin carcinoids do not give these reactions, but they are similar in histological structure to argetaffin.
Non-epithelial tumors of the small intestine are also extremely rare, they are represented by tumors from the muscular, nervous, vascular, adipose tissue. Leiomyoma has the appearance of a node in the thickness of the intestinal wall, more often in the submucosa, without a capsule. The tumor is represented by elongated spindle-shaped cells, sometimes their nuclei are palisadic. Leiomyoblastoma (fanciful leiomyoma, epithelioid leiomyoma) is constructed from rounded and polygonal cells with a light cytoplasm devoid of fibrils. Being a predominantly benign tumor, it can metastasize. Neurilemoma (Schwannoma) is an encapsulated tumor with a palisade-like arrangement of nuclei and sometimes complex organoid structures. With secondary changes, cystic cavities are formed. It is usually located in the submucosal layer. Lipoma is an encapsulated node represented by fat cells. It is usually located in the submucosal layer. Sometimes it reaches a large size, it can cause intussusception and intestinal obstruction.
Hemangioma and lymphangioma are usually congenital, can be single and multiple. Common intestinal hemangiomas are a manifestation of Randyu-Osler-Weber and Parkes-Weber-Klippel syndromes.
Symptoms. Benign tumors of the duodenum initially asymptomatic for a long time and are detected by accident - with X-ray examination of the duodenum or gastroduodenoscopy, taken on a different occasion, or prophylactically - during clinical examination. When a tumor reaches a large size, it usually manifests itself as symptoms of mechanical obstruction of the small intestine or in the event of a tumor disintegration - intestinal bleeding. A large tumor can sometimes be palpated. In some cases, if the tumor is localized in the area of the large papilla (fusarium) of the duodenum, obturation jaundice may be one of the first symptoms. Benign tumors of the duodenum can be single and multiple.
When X-ray examination (especially valuable X-ray examination in conditions of artificial hypotension of the duodenum), one or several filling defects are determined, the contours of the benign tumor are usually clear, even (unevenness occurs when necrotizing the tumor). Endoscopic research, supplemented with targeted biopsy, in many cases allows you to accurately determine the nature of the tumor and make a differential diagnosis with cancer and sarcoma of the duodenum.
Treatment of benign tumors of the duodenum is surgical. Tumors localized in the area of the large papilla of the duodenum are excised with subsequent implantation of the common bile and pancreatic duct into the duodenum. When removing polyps in the area of the large papilla of the duodenum (feces), as evidenced by the data of V. V. Vinogradov et al. (1977), in half the cases, the improvement occurs immediately after the operation, in the remaining cases - within a few months after it. Recently, it has become possible to remove small polypous tumors of the duodenum with duodenofibroscopy.
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