Appendix carcinoid

Introduction to appendix carcinoid Carcinoidofappendix is the most common type of gastrointestinal carcinoid, mainly located in the submucosal layer of the appendix. 70% to 90% of appendix carcinoids are less than 1 cm. There are no obvious symptoms in the clinic. Most of them are found in the operation or found after surgery because of the acute appendicitis. The prognosis is better than other cancers. The disease occurs in women, with a male to female ratio of 1:2 to 4. The average age of onset is 38 years old, and the peak incidence is between 15 and 29 years old. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: lung cancer, liver cancer, abdominal abscess

Iris carcinoid cause

Genetic factors (20%)

Genetics is a phenomenon similar between biological parents and offspring, and between offspring individuals. It is a phenomenon in which the protagonist's traits are expressed in the next generation. That is the phenomenon that genetic material is passed on from generation to generation.

Neuroendocrine tumor (25%)

It is a cancer of the origin of the adrenal gland, which is the most common cancer in neonates. Among them, 32% of neonates are associated with skin metastases, and 3% of other age groups are associated with skin metastases. In elderly patients, carcinoid tumors occasionally metastasize to the skin. Bronchial carcinoids are the most common primary tumors that metastasize to the skin. Merkel cell carcinoma often recurs locally and metastasizes to distant sites including the skin. Such as rotten tail cancer.

Polyp caused (22%)

It is a group of tissues that cover the mucosa and submucosa with fibrovascular core as the core. After forming a protrusion, it is called polyp and can also cause appendix carcinoid.

Inflammatory bowel disease (15%)

It is a special chronic intestinal inflammatory disease, mainly including inflammatory bowel disease of Crohn's disease (CD) and ulcerative colitis (UC), which can also cause appendix carcinoid.

Pathological features

Carcinoid is a low-grade malignant tumor of Kultschitzky cells originating from the Lieberkuhn crypt. It is benign at the beginning and becomes malignant at the beginning, but unlike adenocarcinoma, it is called carcinoid, due to the intracellular particles. It has a clear affinity for silver, also known as argyrophilic cells, which secrete serotonin, which can produce a range of systemic symptoms, including flushing or purplish on the face and upper body, abdominal cramps, diarrhea, asthma and difficulty breathing. There is a manifestation of so-called carcinoid syndrome such as right heart failure, subendocardial fibrosis and secondary valvular insufficiency, and pericarditis with exudation.

Pathological morphology

(1) Gross morphology: The tumor is located under the mucosa of the tail of the appendix, nodular, mostly 0.1-1.5 cm in diameter, a few more than 2 cm, hard and grayish white, the boundary is quite clear, but there is no envelope (Figure 1), may be accompanied by flushing Inflammation of edema, exudation, etc., when the tumor is large, ulcers, erosions, and hemorrhage may occur. The carcinoid located in the tail often forms a typical "bell hammer" structure, the body carcinoid is larger than the tail, and the appendix wall is thickened, or It grows in a ring shape.

(2) Histomorphology: Most of the cells under the microscope are cluster-like or nest-like growth, island-like and glandular tubular arrangement; a few cancer cells are scattered, infiltrating and growing, according to histological features, common appendix carcinoids have three types:

1 Island type: a solid nest formed by small, single cells, occasionally accompanied by acinar or rosette formation, mitotic figures are very rare.

2 gland type: has the characteristics of gland formation, common two subtypes: A. tubular glandular carcinoma, cells are glandular, arranged in order, no solid nest, lack of mitotic figures, occasionally a large number of cytoplasm Eosinophilic granules, 75% of cases are positive for silver staining, 89% are positive for silver staining; B. goblet cell type adenocarcinoma, the tumor consists of small and consistent signet cell nests, often arranged in a micro-glandular tube. Sometimes with extracellular mucus, mucus cardin and CEA staining were consistently positive (Fig. 2C), and in about 88% of cases, argyrophilic staining showed cytoplasmic fruits, some of which might be in the same cell, 3 mixed.

(3) Immunohistochemistry: Immunohistochemical staining of neuroendocrine markers can be expressed in a variety of appendix carcinoids, showing neuron-specific enolase (NSE), chromogranin, protein gene product 9.5, serotonin, Calbindin-D28k (calbindin-D28) is positive, keratin staining is generally weaker than ileal cancer, NSE sensitivity is high, but the specificity is poor, it is suitable for diagnostic screening indicators.

Transfer route

Most of the appendix carcinoids are benign. The pathological sections show that the tumor is limited to the submucosa, no serosal metastasis. The malignant diameter is more than 2cm, the surface is erosive or ulcerated. The pathological section shows that the tumor has infiltrated the muscular layer or is accompanied by lymph node and liver metastasis. Lymph node metastasis and hematogenous metastasis of appendix carcinoids are rare. Mac Gillivray et al found that only 9% of tumors less than 2 cm invaded the appendix mesangium, while Moertel found that only 2 of 144 appendix carcinoids had lymph node metastasis, and appendix carcinoids were directly Invasion of adjacent tissues, such as the cecum, ureter, etc., late abdominal and posterior peritoneal metastasis, lymph node metastasis mainly along the appendicular mesenteric lymph nodes, right colonic artery root lymph nodes, abdominal aortic lymph node pathway, blood transfer is mainly liver, followed by lung, Brain, bone, etc., but very rare.

Iris carcinoid prevention

Prevent infection of chronic intestinal inflammatory diseases in life. Early treatment of the primary disease, early detection, early diagnosis, early treatment is the key to the prevention and treatment of this disease.

Iris carcinoid complications Complications lung cancer liver cancer abdominal abscess

Most of the appendix carcinoids are benign. The pathological sections show that the tumor is limited to the submucosa and there is no serosal metastasis. Malignant patients are larger than 2cm in diameter, and there are erosions or ulcers on the surface. Pathological sections show that the tumor has infiltrated the muscle layer or is accompanied by lymph nodes and liver metastasis. Lymph node metastasis and hematogenous metastasis of appendix carcinoid are rare. The appendix carcinoid can directly invade adjacent tissues, such as the cecum, ureter, etc., and the abdominal and posterior peritoneal metastases may occur in the late stage. Lymph node metastasis mainly along the appendicular mesenteric lymph nodes, right colonic artery root lymph nodes, abdominal aortic lymph node pathway. Hematogenous metastasis is mainly liver, followed by lung, brain, bone, etc., but it is very rare.

Iris type of cancer common symptoms, flushing, redness, abdominal pain, slow growth, hypotension, carcinoid syndrome, intussusception

In 1895, Glazebrook reported the first case of appendicoid carcinoid. The tumor generally grew slowly, with no clinical symptoms in the early stage, or atypical symptoms, no specificity, often due to acute, chronic appendicitis (57%), sometimes chronic Abdominal pain or painless bloody stools, generally do not appear facial flushing, hypotension, asthma, heart valve disease and other carcinoid syndrome, if any, suggest that carcinoid metastasis, mainly liver and posterior peritoneum, Wilson collected 1700 cases, Only 6 cases of carcinoid syndrome have occurred, and some scholars have suggested that the incidence of intussusception of appendicoid carcinoids is high.

Examination of appendicoid carcinoid

1.24h urine 5-hydroxyindoleacetic acid (5-HIAA) determination.

2. Histopathological examination.

3. Immunohistochemistry and electron microscopy.

4. Silver staining with silver.

5. X-ray barium enema: When the appendix is filled with tincture, it can be seen that there is irregular circular filling defect in the distal cavity, the local lumen can be enlarged, and a few carcinoids occur in the base, then the appendix can not be developed.

6. B-ultrasound examination: B-ultrasound examination of the right lower abdomen may find that the appendix is agglomerate, the density is uniform, and the border is relatively clear echo, but since the appendix carcinoids are mostly less than 2cm, and most of them are located at the tail of the appendix, they are The diagnosis has some value, but the sensitivity is not high and it is not specific.

Diagnosis and differentiation of appendix carcinoid

Diagnosis should be clear whether the tumor is benign or malignant, whether it is accompanied by metastasis, metastasis is the standard for clinical diagnosis of malignancy. Histology can make a preliminary judgment from the diameter of the tumor and the infiltration of surrounding tissues. Yang Feng believes that the size of the tumor can be used as a judgment. Whether there is a reliable indicator of the degree of metastasis and malignancy: that is, the diameter of the appendix carcinoid <0.5cm can be regarded as benign; the diameter of 0.5 to 1.5cm can be regarded as a borderline tumor; the diameter >1.5cm has a clear transfer or diameter >2cm It is considered to be low-grade malignant, and whether it has a muscular or serosal invasion is not an indicator of the degree of malignancy.

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