small bowel carcinoid
Introduction
Introduction to small intestine carcinoid Small intestine carcinoid is a tumor originating from the intestinal mucosal Kulchitsky cells. Kulchitsky cells are also called enterochromic cells. The typical intestinal chromaffin cells contain secretory granules, which are obviously dyed yellow after treatment with potassium dichromate. Strong argyrophilicity, stained with silver nitrate solution after formaldehyde fixation, granules stained brownish black. basic knowledge The proportion of illness: 0.002%-0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: intestinal obstruction, intussusception, asthma
Cause
Intestinal carcinoid cause
(1) Causes of the disease
Small bowel carcinoids are cells derived from the acinar cells of the intestinal wall. They are tumors that produce small molecular peptides or peptide hormones, namely APUD cell tumors.
(two) pathogenesis
1. Histochemistry and immunohistochemistry
Small intestine carcinoid originates from Kulchitsky cells in the base of intestinal mucosa. Kulchitsky cells are also called enterochromaffin cells. Typical intestinal chromaffin cells contain secretory granules, which are pro-silver at the histochemical level. Cell carcinoma, small intestine carcinoid diarrhea positive, mucosal staining is usually negative, immunohistochemical staining, such as NSE, chromogranin A, synaptophysin and other positive, suggesting that the tumor has two-way differentiation of epithelial and neuroendocrine.
2. Pathological morphology
(1) Gross morphology: About 80% of small bowel cancers occur in the range of 60 cm in the ileum, which grows under the mucosa, mostly submucosal nodules of 1 to 3 cm, which are broad-based polyps, occasionally greater than 10 cm. The cut surface is grayish white or light yellow, with clear boundaries and hard texture. In some cases, only the submucosal layer is thickened, or polypoid bulge, the tumor surface is covered with normal mucosa, ulcer or bleeding is rare, but 20% to 30% of cases can be Multiple cancerous lesions can have several or dozens of cancerous lesions. In addition, about 20% of small intestinal cancer patients have coexisting tumors in other parts of the body at the same time or later. The reason for this is unclear. Small intestine carcinoid growth is quite slow.
(2) Histomorphology and classification: under the microscope, the tumor cells are small, the shape is the same, round or polygonal, the nucleus is small and regular, the cytoplasm is mildly basophilic, and there are silver particles and lipid-containing vacuoles. Containing serotonin, the tumor cells form a nest, sometimes with a pseudo-purple-like structure. The benign and malignant carcinoids do not depend on the cell morphology, because of the metastatic carcinoid, the cells are morphologically and constricted. Most of the cells have no difference, so the distinction between benign and malignant is judged by the presence or absence of metastasis.
The traditional concept holds that carcinoid tumors are low-grade malignant tumors. However, with in-depth study and follow-up observation of the tumors, it is found that different types of carcinoids have different biological behaviors and different degrees of malignancy. Three categories:
1 typical carcinoid: it consists of closely arranged multi-focal solid masses or small islands, which can be arranged into trabecular, ribbon-like, small tubular, acinar or chrysanthemum-like cells. Small, uniform size, round or polygonal, unclear cell boundaries, fine chromatin, nucleoli are not obvious, mitotic figures are rare, and belong to low-grade malignant tumors.
2 atypical carcinoid: its histological features are similar to typical carcinoid tumors, but tumor cells with a certain degree of atypia, showing nuclear pleomorphism, nuclear chromatin increased, nucleoli clear, mitotic figures more common, and visible Focal necrosis of tumor cells is a moderate malignant tumor.
3 poorly differentiated neuroendocrine carcinoma (small cell carcinoma): its ovial cell carcinoma resembling lung, small cancer cells, less cytoplasm, deep nuclear staining, round or short fusiform, nucleoli are not obvious, cancer cells are not arranged Regular solid mass or cord, common necrosis, is a highly malignant tumor.
3. Transfer route
Carcinoids have the characteristics of invasive growth of malignant tumors. Invasion of cancer destroys the mucosa, muscle and serosal layers and peripheral fat connective tissue, and can be immersed in lymphatic vessels. Blood vessels cause distant metastasis, and blood transfer usually to liver, lung, to diagnosis. When clear, most small intestine carcinoids have penetrated the intestinal wall (70% to 80%), which can directly infiltrate the mesentery, causing shortening and entanglement of the small mesentery. Lymph node metastasis is more common, and about 30% to 40% have lymph node metastasis. The most common hematogenous metastasis is the liver (about 30%). The liver metastases are often several times larger than the primary tumors. The presence or absence of metastasis is closely related to the size of the tumor. It is reported that only 2% of the tumors are <1cm in diameter, 1~ About 25% of 2cm metastasis occurred, and >2cm of 80% had metastasis.
According to foreign reports, the degree of carcinoid metastasis is related to the size and origin of the tumor. In the first operation of ileal carcinoid, 35% to 40% of regional lymph node metastasis can occur. If the tumor is 1 to 2 cm in diameter, 50% of patients can undergo metastasis. Tumor diameter is greater than 2cm, 80% to 90% of patients will metastasize, another manifestation of small intestine carcinoid is often coexisting with the second primary tumor of different tissue sources, carcinoid patients coexisting the second primary tumor as much as 30% to 50 %.
4. Biological characteristics
Small intestinal carcinage is an APUD cell tumor that secretes some vasoactive substances such as serotonin, bradykinin, histamine and catecholamine. More than 40 peptide hormones are decomposed by monoamine oxidase in the liver and lung. 5-hydroxyindoleacetic acid, excreted in the urine, if the tumor releases a large amount of vasoactive substances such as serotonin, which is not completely decomposed in time, it can cause carcinoid syndrome, and about 10% of patients with small intestinal cancer appear typical The carcinoid syndrome, at this time, the vast majority of liver metastases, it is estimated that in the presence of carcinoid syndrome, intestinal carcinoids have grown for an average of 9 years.
The main substances producing carcinoid syndrome are serotonin and bradykinin. These biologically active substances flow into the liver through the portal vein blood, and are inactivated by the cells after inactivation by the cells. Only when the liver metastasizes the tumor to secrete a large amount of active substances directly When the hepatic vein is released to the whole body, or when the tumor releases a large amount of active substances and is not completely destroyed, the patient can develop carcinoid syndrome. Serotonin has direct contraction to peripheral blood vessels and pulmonary blood vessels, and also has strong contraction effect on the bronchi. It has a stimulating effect on the preganglionic vagus nerve and ganglion cells, which increases the motility of the gastrointestinal tract, increases secretion, and increases the circulating serotonin concentration, which may also cause endocardial fibrosis.
Carcinoids are tumors of neuroendocrine cells and have the following three characteristics: 1 high amine content; 2 amine precursors; 3 amino acid decarboxylase, deearboxy-lation The amine precursor material is converted to an amine peptide hormone.
Prevention
Intestinal carcinoid prevention
1. Do not drink alcoholic beverages for a long time, quit smoking and drinking hobbies, do not overeat pickles, sour, spicy and irritating foods, and banned mildew foods. It is more important for people with chronic pharyngitis to develop good eating habits. If you are less than enough, eat more fresh fruits and vegetables.
2. Maintain proper temperature and humidity in the cold season, pay attention to air circulation. Room temperature should be 20 ° C, do not cover too much bedding when sleeping at night, to avoid excessive temperature or excessive drying, causing throat discomfort. Do not sleep in the wind, take a break after strenuous labor, do not rinse the cold bath immediately. Those with acute pharyngitis caused by colds should drink hot water or ginger soup to increase sweating. Note that the stool is smooth. Timely treatment of acute inflammation, to prevent the evolution of chronic, chronically diseased organs, more likely to malignant.
3. Strengthen labor protection. Harmful gases, dust, such as dust, chlorine, bromine, iodine, etc. in the production process need to be properly disposed of. Workers who have been in contact with harmful chemical gases for a long time should wear gas masks and protective gowns.
4, increase physical fitness and strengthen physical exercise. Commonly used cold water to wash your face, prevent colds, have labor and leisure, life is regular, outdoor activities in the morning or work.
Complication
Intestinal carcinoid complications Complications, intestinal obstruction, intussusception, asthma
Intestinal obstruction, intussusception, endocardial fibrosis, asthma, etc. are common complications of small intestine carcinoid.
Intestinal obstruction
It is not caused by the tumor invading into the abdominal cavity, but the tumor infiltration and growth locally causes significant fibrous tissue hyperplasia to appear in the mass, causing intestinal obstruction.
2. Central nervous system symptoms
Mental retardation, nervousness, nervous disorder, sweating, etc.
Symptom
Small bowel cancer symptoms Common symptoms Awareness under the abdomen masses Right heart failure Skin rough diarrhea Bronchospasm niacin deficiency Abdominal distension Abdominal pain
Carcinoids often have no symptoms or specific symptoms in the early stage. Most patients find that they can be examined by endoscopic examination and biopsy. After pathological histology, occasionally, tumor enlargement or intussusception occurs, and intestinal obstruction occurs. The symptoms only occur.
Intestinal obstruction
Obstruction caused by small intestine carcinoid is often caused by tumor infiltration and local growth caused by significant fibrous tissue reaction, resulting in intestinal stenosis or intestinal fistula adhesion or aggravation of the intestine, caused by intussusception, rather than the tumor protruding into the intestinal lumen, and The diameter of the tumor is irrelevant. The abdomen can touch the mass and the bowel sounds hyperthyroidism.
2. Carcinoid syndrome
It refers to a series of obvious and harmful symptoms caused by the release of a large number of peptide amine hormones into the blood circulation of carcinoid tissue cells. It was officially named in 1954 by Thonson. It is due to the growth of carcinoid tissue to a certain extent and liver metastasis. The emergence of a group of clinical manifestations, often appear to mark the carcinoid has advanced or in the advanced stage, about 10% of patients with small intestine carcinoid have carcinoid syndrome, the clinical manifestations mainly involve skin, digestion, respiration, heart, muscle, Six systems, such as nerves, have some episodes of seizures, each episode lasts for a few minutes, but some symptoms are persistent.
(1) paroxysmal symptoms:
1 skin: paroxysmal flushing, is the most common and early symptoms, about 70% of patients can have this performance, presenting four types: one is diffuse red flushing, with face and neck, front chest, also Can be spread throughout the body, each episode lasts for a few minutes, intermittent skin is normal, second is purple bright red, flushing is the same as the first type, but lasts for a long time, the face is cyanotic, and there are small venous plexus, eye-binding membrane Redness and tearing, the third is that the skin is not too bright red, the color is between the above two types, the duration can be several hours, or even 1-2 days, the fourth is the bright red patchy flush, the most obvious on the base of the neck .
2 gastrointestinal symptoms: watery diarrhea, mainly in the case of severe 20 to 30 times a day, a large number of water and electrolytes lost, diarrhea often coincides with the degree of skin flushing, such as the removal of carcinoid primary lesions and liver metastases, Diarrhea can be stopped, a very small number of patients may have malabsorption syndrome, accompanied by diarrhea often abdominal pain, abdominal distension, bowel, caused by intestinal obstruction caused by cancer or fibrous tissue, some patients may have swollen swelling when liver metastasis The liver has tenderness.
3 Asthma, bronchospasm: often occurs at the same time as the skin flushing episode, the lighter is hyperventilated, the severe asthma and dyspnea, and severe suffocation due to bronchospasm.
4 hemodynamic changes: can cause blood pressure fluctuations, vasodilatation collapse.
(2) persistent symptoms:
1 facial telangiectasia, red or slightly purple.
2 facial or limb edema, associated with increased venous pressure and antidiuretic effects of serotonin.
3 In vivo due to lack of niacin, the patient's skin is rough, and even rough skin lesions appear.
4 valvular heart disease is a late symptom of carcinoid syndrome. The rapid-speed hormones such as neurokinin A and substance P produced by cancer-like cells stimulate the valve fibrosis. The subendocardial fibrous tissue proliferates and the heart valve is thickened. Shortening, the right heart changes obviously, the left heart is lighter, the main involvement is the tricuspid valve and the pulmonary valve, making it narrow or incomplete, and right heart failure occurs, which is caused by intestinal carcinoid and liver carcinoid tissue. Peptide amines, which enter the hepatic vein and inferior vena cava, first reach the right heart and cause right heart lesions. About 1/3 of the patients have the above-mentioned valvular disease. Clinically, heart disease is the leading cause of death in carcinoid patients.
5 fibrotic lesions: in addition to the heart, cellulose deposition in the pleural cavity, peritoneal cavity, pericardial cavity, and cause the corresponding clinical symptoms, abdominal fibrosis can occur abdominal mass, causing intestinal obstruction.
6 central nervous system symptoms: mental retardation, nervousness, nervous disorder, sweating, etc., there are still anorexia, fatigue, fever and so on.
3. Carcinoid crisis
In the process of anesthesia and surgery, a group of cancer patients suddenly enter the blood circulation, a group of syndromes that endanger the patient's life, mainly characterized by severe persistent skin flushing, hypotension, bronchospasm-induced breathing. Difficulties, suffocation, confusion, and gradually into a coma, if you do not do urgent treatment, you can die at any time.
Examine
Intestinal carcinoid examination
1. Determination of serotonin (5-hydroxytryptamine 5-HT)
The level is raised to 0.5 to 3.0 g/ml (normal value 0.1 to 0.3 g/m1).
2. Determination of urine 5-hydroxyindoleacetic acid (5-HIAA)
In most patients with metastatic carcinoid tumors, 5-HIAA in the urine exceeds 30mg/24h, usually 60-100mg/24h (normally 6-9mg/24h), and fasting can produce false positive results 2 to 3 days before the measurement. Food and medicine, but those with normal 5-HIAA cannot rule out carcinoid syndrome, and other biologically active substances should be tested.
3. Endoscopy duodenum
The end of the ileum can be found by fiber duodenum and colonoscopy. The carcinoid is mainly at the end of the ileum. Through the fiberoptic colonoscopy, the ileum segment 30~40cm away from the ileocecal valve can be examined. The polypoid lesions can be seen in the broad-based, biopsy. Can be diagnosed, for small polypoid lesions, can be removed by endoscopic high-frequency electric, is also one of the treatment.
4. Selective mesenteric angiography
It is of great value for the diagnosis and differential diagnosis of carcinoid tumors. The image shows the radial small arteries around the tumor, the branches of the arteries increase, shift, the normal structure of the small and small blood vessels disappears, and the tumor blood vessels are unevenly divided and interrupted. The tumor can be stained, the tumor is light, moderately stained, the border is clearer, often star-shaped; the drainage vein is invaded, narrowed, and the varicose veins around the tumor; no tumor blood vessels, no early vein development: mesenteric artery branch Irregular stenosis, obstruction, distortion, etc., mainly caused by carcinoid invasion of the mesentery or serotonin-induced mesenteric fibrosis. Multiple lesions of small intestinal carcinoid lesions and changes caused by mesenteric lesions can be differentiated from other small intestinal tumors.
5. Ultrasound, radionuclide scanning, CT examination
It can be seen whether there is intrahepatic space-occupying lesions. CT scan can show a mesenteric mass larger than the primary tumor, accompanied by calcification and fiberopticles extending to the surrounding area, suggesting mesangial mesangial metastasis.
6. X-ray barium angiography
Because of small submucosal tumors of the small intestine, when the tumor is small, X-ray barium angiography is not easy to find. When the tumor grows into the intestine or infiltrate the intestinal wall and causes intestinal stenosis, it can show polypoid filling defect or intestinal intestine. In the case of a set of signs, the enlargement of the lesion and the mesentery may indicate that the extraintestinal mass is displaced adjacent to the intestinal fistula. The traction of the mesentery causes the intestinal fistula to be arranged in a convergent manner, the intestinal wall is distorted, the intestinal lumen is narrow, and even obstruction, and severe cases may cause the mesentery. Arterial atresia leads to ischemic necrosis of the small intestine.
Diagnosis
Diagnosis and diagnosis of small intestine carcinoid
diagnosis
The diagnosis of carcinoid is difficult. Due to the lack of special signs, it is often asymptomatic and rare in the early stage. Most of them are accidental findings. They are often misdiagnosed clinically. When patients have typical carcinoid syndrome, the diagnosis is easier, and there are many liver metastases. Increased serotonin levels and/or increased urinary 5-hydroxyindoleacetic acid (5-HIAA) may be highly suspected of carcinoid syndrome.
According to skin flushing, diarrhea, abdominal pain, asthma, right heart valve disease and hepatomegaly, it may indicate the presence of carcinoid syndrome.
clinical diagnosis
1. Clinical manifestations.
2. Laboratory and other auxiliary inspections.
Differential diagnosis
Enteral tuberculosis
Intestinal tuberculosis may have abdominal pain, diarrhea or constipation, lumps and other manifestations, sometimes easily mistaken for cancer, but intestinal tuberculosis is accompanied by fever, night sweats and other tuberculosis toxemia, and often accompanied by extraintestinal tuberculosis, gastrointestinal X-ray Tincture examination showed signs of irritability, filling defects or stenosis in the ileocecal area. There were ulcers, stiffness, and stenosis in the lesions of the colonoscopy. The biopsy revealed typical tuberculosis lesions - cheese-like granuloma, anti-tuberculosis treatment. Effective, can be identified with small intestine tumors.
2. Crohn's disease (Crohn's disease)
Can also be expressed as abdominal pain, diarrhea, abdominal mass and weight loss, anemia, fever, etc., gastrointestinal X-ray angiography showed intestinal stenosis, tube wall stiffness, sputum bar-like, line-like signs, lesions in segments Sexual distribution, the most common in the terminal ileum and right colon, colonoscopy showed a segmental distribution of lesions, the mucosa between the two lesions was completely normal, the mucosa of the lesion was pebbly, or a fissure ulcer, visible in chronic cases Intestinal stenosis, inflammatory polyps, mucosal biopsy can sometimes find non-case-like granuloma, which can be identified above.
3. Fungal enteritis
Fungal enteritis can also cause abdominal pain, diarrhea, weight loss, malabsorption, etc., but generally does not cause intestinal obstruction, intestinal perforation, intussusception, etc., identification mainly by serum or fecal fungus culture or found in the feces hyphae or spores .
4. Celiac disease
Also known as non-tropical steatorrhea, mainly found in children and young people, often have a family history of pasta intolerance, identification mainly depends on the quantitative determination of fecal fat, various intestinal absorption function tests, gastrointestinal X-ray examination, duodenal mucosa Biopsy, etc. In addition, the serum alcohol-soluble gliadin antibody, endomysial protein and reticulin IgA antibody are often positive in the patient's serum, and the symptoms can be quickly resolved after fasting with the glucan-containing diet.
5. Secondary small intestinal malignant tumor
More common, melanoma is the most common tumor that causes small bowel cancer. Breast cancer is also common in the small intestine. Others such as cervical cancer, ovarian cancer, colon cancer and kidney cancer can also directly invade the small intestine or directly through the retroperitoneal lymph nodes. Invasion of the duodenum, identification mainly depends on active systematic examination, found primary cancer, such as imaging examination (X-ray, B-ultrasound, CT, etc.) and endoscopy plus histological biopsy, etc., if necessary, laparotomy .
