Colon carcinoid

Introduction to colon carcinoid Colonic carcinoid (coliccarcinoid) originates from the argyrophilic Kultschitzky cells of the intestinal mucosa, also known as argyrophiloma. Because its tumor cells originate from the endoderm, they are arranged in a nest, and are pathologically similar to the morphology of cancer. They are called carcinoid and are low-grade malignant tumors. basic knowledge The proportion of sickness: 0.007% Susceptible people: no special people Mode of infection: non-infectious Complications: heart failure, shock, malnutrition

Colon carcinoid cause

(1) Causes of the disease

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(two) pathogenesis

Pathophysiology (27%):

In colonic carcinoid, 68% is located in the right colon, of which the cecum accounts for 50%, the right colon and the appendix, the jejunum originates from the midgut, and its carcinoid cell type is 65% argentaffin, 35% genus. The difference between argyrophil, nucleophilic and argyrophilic cells is that the former secretes 5-HT, while the argyrophilic cells secrete other functional active substances, so the right colon colon cancer originating from the midgut is in the late course of the disease. Or accompanied by liver metastasis can produce carcinoid syndrome, which is due to the 5-HT secretion of carcinoid pro-silver cells exceeds the body's ability to degrade, at this time the blood 5-HT level is higher than normal, in vivo After 5-HT is decomposed, the amount of 5-hydroxyindoleacetic acid (5-HIAA) in the urine is also increased in 24 hours. The left colon and rectal cancer cell lines derived from the hindgut are non-affinitive and do not secrete 5-HT. Therefore, advanced rectal carcinoids do not produce carcinoid syndrome even with liver metastases.

(1) Histological origin: the organization of colon carcinoid, most scholars believe that Kulchitsky cells from endoderm, according to the Williams and Sandler method, colon carcinoids belong to the sub-group derived from the hindgut, with colon cancer Increased year by year, its occurrence seems to exceed the distribution of endoderm epithelium, plus the presence of neuroendocrine particles in the cytoplasm of tumor cells, and some tumor cells can produce functional serotonin (this substance and normal central nervous system) The system's neurotransmitter serotonin functions the same, so recent data support colonic carcinoids that originate in the neuroendoderm and are neuroendocrine tumors.

(2) Macroscopic morphology: Colonic carcinoids are mostly located in the deep part of the mucosa, which are spherical or lenticular, with nodular or polypoid protrusions to the intestine, with no pedicles on the broad base, a small number of pedicles, small volume, and the diameter is generally 1.5. Below cm, occasionally more than a few centimeters, the tumor is hard, the boundary is clear, the surface has normal mucosal coverage, a few can appear ulcers, form a umbilical appearance, the cut surface is grayish yellow or white, the boundary is clear, some cases only show Submucosal local thickening, or broad-based polyposis to the intestinal cavity uplift, colonic carcinoid multiple, the tumor surface covered mucosa is generally intact, mucosal ulcer or bleeding is rare compared with adenocarcinoma, rectal carcinoids are found to be rare, its tumor The body diameter is often less than 1cm, and it can be active. More than 1cm of tumor often protrude into the intestine to form a sacral mass with ulcer, occasionally intestinal stenosis, more common in nodular and polypoid.

(3) Histomorphology: The cell morphology of colon cancer also has different differentiation. The typical carcinoid is composed of well-differentiated cells. The cell is small in shape, polygonal, oval or low-column, medium-sized, eosinophilic. Nuclear round or oval, not deeply stained, located in the center of the cell, no obvious nucleoli, nucleoscles are rare, nuclear shape and cell shape are consistent, often arranged in a nest-like shape, cord-like, glandular, in 1 In the tumor, the tumor cells can be arranged in one arrangement, or the above three forms can exist simultaneously. Under the electron microscope, spherical neuroendocrine particles can be found in the cytoplasm of the tumor cells, and one of these neurosecretory particles is located at the central or partial position. The core of different electron density and morphology, the core is surrounded by a membrane, the core and the membrane have different widths of air halo, the shape and size of the secretory particles vary greatly, and the diameter of the secretory particles of colon cancer cells is large. At 100 to 300 nm.

(4) Histochemical characteristics: The pathological histochemical detection method of colonic carcinoid is mainly argyrophil staining, black particles can be seen in the cytoplasm of argyrophilic staining, and the carcinogenesis of different parts of the carcinoid also has different effects on silver staining. Carcinoid in the intestine, the cytoplasmic granules are large, round and uniform in size, and some argyrophilic staining is positive. The argyrophilic staining of rectal carcinoid is about 55% negative, but it is also positive for argyrophilic staining (28%). .

(5) Immunohistochemical features: The most sensitive immunohistochemical marker is chromogranin. The positive expression of this marker is the most reliable basis for the diagnosis of carcinoids in addition to histological morphology. Other markers, such as nerves The positive expression of meta-specific enolase (NSE) and cytokeratin has positive evidence for the diagnosis of carcinoid. Immunohistochemistry shows that 90% of the midgut carcinoid is serotonin positive and 90% of the hindgut Carcinoids are positive for pancreatic polypeptide, and rectal carcinoids can be positive for cytokeratin, NSE, chromogranin A and synaptophysin.

The nature of colon carcinoid is mainly determined by its biological behavior, not histological morphology. Most colonic carcinoids have the characteristics of invasive growth of malignant tumors despite slow growth and long course of disease. Invasion of cancerous tissue destroys local pipeline wall. Invade surrounding tissues, invade lymphatic vessels, blood vessels, form local lymph nodes or even metastasis of distant organs. Blood metastasis often forms metastases in the liver, followed by lungs. The rate of metastasis is related to the size of the primary tumor and the location of the primary tumor. The primary tumor <1cm, with complete capsule, the transfer rate is 15%, >1cm, more than 50% metastasis, >2cm are almost accompanied by regional lymph node and intrahepatic metastasis, colonic carcinoid metastasis rate is the highest , 52% to 72%, local lymph nodes or liver metastases during surgery, poor prognosis; rectal carcinoid metastasis rate of 17% to 35%, carcinoid, especially metastatic tumors with better differentiation, growth Compared with other malignant tumors, metastatic cancer is slow, and even if there are metastases, it can survive for several years. Therefore, most carcinoid cases include cases with metastasis, and surgical treatment can achieve good results.

Colonic carcinoids are characterized by multiple or multi-source tumors, with an incidence of 2% to 4.5%, but 25% to 35% of smaller intestinal carcinoids are low. Kuiper reports that the incidence of malignant tumors in other carcinoid tumors is higher. 29% to 47%, far higher than other tumors (5.1% to 7%), and more than half of the combined tumors are in the gastrointestinal tract. Because concurrent tumors tend to have a worse prognosis than carcinoids themselves, when there is carcinoid, You should look for other parts of the malignant tumor.

Pathological type (20%):

Williams classifies gastrointestinal carcinoids according to embryogenesis and blood supply: 1 foregut carcinoid: including stomach, duodenum 1, 2, pancreas; 2 midgut carcinoid: including duodenum 3 , 4 segments, empty ileum, appendix and ascending colon; 3 posterior intestinal carcinoid: including left colon and rectum.

According to the difference of silver cancer staining reaction, the carcinoid is divided into two types: pro-silver and non-intra-silver. The foregut cancer cells produce a variety of hormones, so the amount is small, so there are few symptoms in the clinic. Intestinal cancer cells mainly secrete serotonin, etc., and their secretion exceeds the degradation ability of the liver. Especially when there is liver metastasis, the symptoms of carcinoid syndrome often appear. The cancer cells of the hindgut can secrete various peptides. Substances, such as somatostatin, enkephalin, substance P, etc., have few manifestations of carcinoid syndrome.

According to the pathological type, the carcinoid is divided into typical carcinoid and atypical carcinoid. Atypical carcinoid is a poorly differentiated carcinoid, which often suggests more malignant behavior. The prognosis of typical carcinoid is better than that of atypical carcinoid.

The histological structure of colon carcinoid can be divided into 4 types:

(1) Adenoid-like type: The cancer cells are closely matched to each other and form a glandular or acinar-like shape, a chrysanthemum-like group, a band, etc., and the cells are mostly low-columnar.

(2) Strip type: The cancer cells are arranged in a solid line, or the double-row cell lines are arranged in parallel to form a streamer-like strip. There is a small amount of connective tissue spacing between the cords, and the interstitial reaction is obviously like hard cancer.

(3) Solid mass type: The cancer cells are arranged in a solid nest-like mass composed of polygonal tumor cells of uniform size, and the nests are separated by a small amount of connective tissue containing capillaries.

(4) Mixed type: The above three types can be arbitrarily mixed.

Transfer route (15%):

The biggest difference between colon carcinoid and other carcinoids is that the metastasis rate is very high. The carcinoid found in the colon is larger than other parts. The average diameter is 4.9cm, which is partly because the right colon is large. Early detection showed that the metastatic site had the most regional lymph nodes, followed by liver, lung and ovary. At the time of surgery, about 60% had local lymph nodes or liver metastases.

Colon carcinoid prevention

Colon carcinoid is a malignant tumor that grows slowly, has a low degree of malignancy, and has a long course of disease. The general prognosis is good, and it can survive for a long time. The prognosis of colon carcinoid depends on its primary site, depth of invasion, tumor size, presence or absence of lymph node and liver metastases, symptoms at presentation, and surgical procedures. A report of 31 cases of colon carcinoid in Chen, Taiwan, showed that the clinical prognosis of aneuploid tumors was poor by flow cytometry. It has also been reported that expression of P53 in colonic carcinoids suggests a poor prognosis in patients and is considered a potential indicator of advanced carcinoid. The general patient's death is due to carcinoid crisis and carcinoid involvement of the heart with heart failure, shock, fluid and electrolyte loss, extreme malnutrition. Therefore, the prognosis of patients with typical carcinoid syndrome is often worse than those without syndrome.

The prognosis of colon carcinoid is worse than other gastrointestinal tracts. The 5-year survival rate is 33% to 52%. The prognosis is related to the presence or absence of metastasis at the time of surgery. The 5-year survival rate of non-metastatic patients is 77%, and the regional lymph node metastasis is 65%, when there is distant lymph node metastasis, it is reduced to 17%. The prognosis of rectal carcinoids is better than that of colon cancer. The general 5-year survival rate is over 80%.

Colonic carcinoid complications Complications, heart failure, shock, malnutrition

The general patient's death is due to carcinoid crisis and carcinoid involvement of the heart with heart failure, shock, fluid and electrolyte loss, extreme malnutrition. Therefore, the prognosis of patients with typical carcinoid syndrome is often worse than those without syndrome.

Colonic cancer symptoms Common symptoms, asthma, blood, chest pain, diarrhea, pulmonary murmur, edema, blood pressure, thin stool, intestinal dysfunction, abdominal pain

General symptoms

Most carcinoids have no obvious symptoms when they are small, and they are often found in occasional cases. If the tumor is long enough to grow or grow in a special site, it often causes some intestinal dysfunction, abdominal pain or different degrees. Obstructive symptoms, appendicoid carcinoids have appendicitis symptoms, clinically misdiagnosed as appendicitis and surgery, rectal carcinoids can be compared with colonic carcinoids, bloody stools or bowel habits change early, but these symptoms are similar to the same site of colorectal adenocarcinoma There is no significant difference in the symptoms caused, so it is difficult to diagnose correctly in clinical practice.

In addition to the symptoms similar to those of colorectal adenocarcinoma, a large number of cases, regardless of their tumor size, may have some specific syndrome called carcinoid syndrome. Observe and study the presence or absence of carcinoid syndrome. Pre-diagnosis and determination of treatment are helpful.

2. Carcinoid syndrome

(1) paroxysmal skin flushing: generally occurs above the chest, such as face, neck, upper chest, etc., which is characterized by scattered clear skin flaky flushing, generally lasting 2 to 5 minutes, can be self-resolved, if time lasts Longer (such as a few hours) will turn purple, local edema, rapid heartbeat, blood pressure, etc., skin flushing is more induced by emotional, overwork or eating, is one of the most common symptoms of carcinoid syndrome .

(2) diarrhea: diarrhea is mostly loose stool or watery diarrhea, 5 to 6 times a day, up to 20 to 30 times, severe cases lead to skin flushing water and electrolyte imbalance, diarrhea often accompanied by temporary abdominal pain, occasionally and other Symptoms appear at the same time. Some people have diarrhea after eating or early morning.

(3) Symptoms caused by fibrous tissue hyperplasia: fibrous tissue hyperplasia often occurs in the serosa or intima, such as the peritoneum, right endocardium (tricuspid valve, pulmonary valve), pleura, pericardium and some small blood vessels Etc., due to the above-mentioned lesions, carcinoid patients have corresponding symptoms and signs, such as tricuspid or pulmonary murmur, chest pain and so on.

(4) Asthma: often occurs with diarrhea or paroxysmal skin flushing, usually lasting about 10 minutes, and is related to bronchial smooth muscle spasm.

Intestinal carcinoid syndrome is the result of a disorder of tryptophan metabolism. Only 1% of tryptophan in normal people is converted to serotonin. When carcinoid syndrome occurs, 60% of tryptophan can be converted into Serotonin.

In the presence of carcinoid syndrome in intestinal carcinoids, it is often accompanied by extensive local metastasis and liver metastasis. Intestinal carcinoids without liver metastasis generally do not cause carcinoid syndrome, because the active substances released by intestinal carcinoids are Blood flow into the liver, which is degraded by a large number of monoamine oxidases present in the liver, so no carcinoid syndrome occurs. Normally, 65% of the serotonin from the intestine is metabolized in the liver, and 33% is inactivated by monoamine oxidase in the lung tissue. A very small amount of serotonin enters the large circulation, so it does not cause physiological disorders. When the carcinoid metastasizes to the liver, the serotonin secreted by the carcinoid can directly enter the hepatic vein and flow through the right heart into the lung. The lung cannot be overloaded. Inactivated serotonin completely, causing it to enter the large circulation, causing carcinoid syndrome. Because the concentration of serotonin in the right heart chamber is higher than that in the left heart chamber, the right endocardial fibrous tissue is more common than the left heart.

Colonic carcinoid is asymptomatic in the early stage. As the tumor progresses, most of them have different degrees of symptoms. However, the clinical manifestations of colonic carcinoid are lack of specificity, which is difficult to distinguish from colon adenocarcinoma. Preoperative diagnosis is difficult. Clinically, it is difficult to diagnose. In the diagnosis of colonic disease, the possibility of colonic carcinoid should be considered, and X-ray barium angiography, B-ultrasound, colonoscopy, etc., as needed, to aid diagnosis.

Colon carcinoid examination

1. Determination of urinary 5-hydroxyindoleacetic acid

Normal human urine 5-hydroxyindole acetic acid is 2-9 mg, and its content exceeds 50 mg to help diagnose carcinoid syndrome. Individuals can discharge up to 2000 mg.

2. Histopathological examination

The morphological characteristics of carcinoid under light microscopy are:

The morphology, size and staining of the 1 type of cancer cell nuclei are more consistent, the mitotic figures are less, the irregularities are not large, and the nucleoli are not prominent.

The cytoplasm of the two types of cancer cells is transparent or eosinophilic fine granules, and may have argyrophilic and pro-silver staining reactions.

The three types of cancer cells are polygonal or round, arranged in a special ribbon, flower ring, chrysanthemum group, antler-like solid nest or adenoid structure, and the cancer cells are evenly spaced and arranged neatly.

Four types of cancer interstitial often have fibrous tissue hyperplasia, and interstitial fibrous tissue hyperplasia with carcinoid syndrome is more obvious.

3 air sputum double contrast

It has a high value for the localization diagnosis of the primary tumor. After examination, it can not only identify the location of the tumor, but also find multiple lesions. The double contrast examination can find early carcinoid tumor with diameter <2cm, colon on X-ray. The damage can be shown in 4 types:

1 lumps type: multiple nodule fusion;

2 polyp type: filling defect-like changes;

3 infiltration type: intestine infiltration stenosis;

4 intestinal obstruction type: the tincture was blocked.

4. Colonoscopy

For patients suspected of having colon cancer, routine surgery should be performed. Colonoscopy is currently the most effective, safest and most reliable method for the diagnosis of intralesional lesions. Most of the early lesions can be found by colonoscopy under colonoscopy. Colonic carcinoid is hemispherical and sessile, and the wall is stiff. The surface mucosa is mostly smooth, grayish white, and the central part is often deformed. The side part may have mucosal congestion, edema, shallow erosion or ulceration. Misdiagnosed as colon cancer, colonoscopy can not only observe the lesion under direct vision, but also take biopsy for pathological examination.

5.B ultrasound and CT scanning

It is of great value to understand the extent of the lesion, the depth of invasion, the presence or absence of metastasis, and the estimated scope of surgery, but it does not contribute much to the qualitative diagnosis of carcinoid.

6. Somatostatin receptor scintigraphy

For carcinoid tumors with tumor diameter <1cm, X-ray angiography, B-ultrasound, CT and other imaging examinations are often difficult to detect and locate, but with 111In-DTPA-D-phe'I-octreotide scintillation scan, 80%-90 Localized diagnosis of % carcinoid lesions, Kwekkeboom with octreotide scanning combined with chest X-ray, upper abdominal ultrasound diagnosis of carcinoid, found that the sensitivity of the combined method was 87%.

Diagnosis and diagnosis of colonic carcinoid

Pathological examination is an important diagnostic method for carcinoids. According to the histological features of the tumor, it is generally not difficult to make a diagnosis.

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