What Is Islet Cell Carcinoma?

Somatostatin islet cell carcinoid (Carcinoid) is a tumor that originates in EC cells and has the function of secreting hormones such as serotonin (5-HT) or 5-hydroxytryptophan (5-HTP).

Islet cancer

Somatostatin islet cell carcinoid (Carcinoid) is a tumor that originates in EC cells and has the function of secreting hormones such as serotonin (5-HT) or 5-hydroxytryptophan (5-HTP).

Chinese name

Islet cancer

Foreign name

Carcinoid

medication

Methyl lysergic acid butanolamide

Disease characteristics

Tachycardia, decreased blood pressure, asthma, etc.

Islet Cell Carcinoid: English Name: Carcinoid Drug Therapy:

Like other functional endocrine tumors, early tumor resection is the preferred treatment for this disease; so are surgical principles and surgical choices. However, even if the disease has metastasized, if the primary carcinoid lesion can be removed, it can relieve or even eliminate the symptoms. For polycentric or metastatic carcinoids that are not suitable for radical resection, it is used as a palliative pancreas or liver Resection also has a certain effect.

Medical treatment of islet cancer

(1) Less or avoid drugs that can promote the release of 5-HT. They include: morphine, halothane, dextran, polymyxin and so on. At the same time, factors such as drinking, mood swings, and strenuous exercise should be avoided or reduced. (2) Histamine 1 and histamine 2 antagonists are used to inhibit carcinoid secretion of histamine and peptide hormones. methyllysergide (methysergide): for the treatment of carcinoid syndrome, 1 to 4 mg once intravenously; or 10 to 20 mg in 100 to 200 ml of normal saline within 1 to 2 hours Intravenous infusion can control skin flushing, asthma and diarrhea. cyproheptadine; 4 to 8 mg each time, 3 to 4 times a day, can relieve symptoms and achieve the purpose of palliative treatment. (3) Tryptophan hydroxylase inhibitors: These drugs can inhibit the activity of tryptophan hydroxylase, thereby reducing the synthesis of 5-HT and alleviating the symptoms of this disease. parachlophenylalanine 1 g each time, 3 to 4 times a day, orally. Can alleviate or reduce the degree of nausea, vomiting, diarrhea and skin flushing. Its side effects can cause central nervous system dysfunction or hypothermia. Methyldopa (methylodpa): Pancreatic carcinoids that secrete 5-hydroxytryptophan can be treated with this medicine, orally 0.25 ~ 0.5g each time, 4 times a day. (4) Somatostatin (somatostatin) can widely inhibit the release of endocrine hormones. It is used in patients with islet cell carcinoid tumors and can inhibit flushing caused by pentagastrin stimulation. (5) Chemotherapy: The application of chemotherapy drugs such as 5-Fu and cyclophosphamide can alleviate the symptoms of this disease, but the efficacy is poor. Pathological changes

EC cells have the characteristics of APUD cells and are widely distributed in the gastrointestinal tract, pancreas and lung. When the carcinoid volume is small and the diameter does not exceed 3.5cm, it generally does not cause symptoms and signs; while the carcinoid volume is large, due to the production of a large amount of 5-HT and other amines and peptide hormones, the liver cannot effectively metabolize, Inactivate the secreted products of these carcinoids, so 5-HT, 5-HTP, bradykinin, pancreatic peptides, etc. all enter the systemic circulation; in addition, when liver metastases occur in carcinoid tumors, the hormones secreted by metastatic liver cancer may not be It is metabolized by liver cells and directly enters the systemic circulation, and acts on target cells, thereby causing carcinoid syndrome.

Parotid skin flushing

Paroxysmal skin flushing (Intermittent flushing): It mainly occurs in the exposed parts of the face, neck, and front chest, and can also spread throughout the body. The occurrence of skin flushing is mostly paroxysmal and sudden, and it is bright red or dark red. The duration ranges from several minutes to 1 to 2 days, but the skin color of patients of black race or dark complexion may not be obvious. If the course is longer, fixed skin changes may occur at the site of frequent attacks, with local dilation of most of the small blood vessels and dark red skin. The factors that affect the onset of skin flushing can be: alcohol, pain, mood swings, and physical activity can induce skin flushing, and adrenaline and norepinephrine can also promote the onset of skin flushing; the use of alpha-adrenergic blockers can prevent skin flushing happened. When skin flushing occurs, patients often have tachycardia, hypotension, orbital edema, and gastrointestinal and pulmonary symptoms.

Cardiovascular system symptoms

Cardiovascular system symptoms: Patients with skin flushing may be accompanied by tachycardia, decreased blood pressure, and even shock; late-stage heart valve disease or congestive right heart failure may occur.

Respiratory symptoms

Respiratory symptoms: 20-30% of patients may develop asthma and dyspnea while paroxysmal skin flushing occurs, similar to bronchial asthma. Its mechanism is caused by bronchial smooth muscle spasm caused by substances such as 5-HT.

Digestive symptoms

Digestive system symptoms: Patients may be accompanied by abdominal pain, bloating, diarrhea and other symptoms to varying degrees. Abdominal pain is mostly related to the location of the primary tumor and / or metastatic cancer, and the squeezing and destruction of surrounding tissue when the tumor is enlarged. Diarrhea is mostly watery. In severe cases, it can reach 10 to 20 times a day. It should be distinguished from WDHA syndrome.

Other symptoms

Other symptoms: Accompanied by pancreatic islet cell carcinoid, sometimes other endocrine hormones may be manifested, such as insulin, glucagon, growth hormone, parathyroid hormone, adrenocorticotropic hormone, etc., generally have corresponding characteristics Performance can be identified. At the late stage of carcinoid tumors, cachexia, such as weight loss, anemia, and hypoproteinemia, can also occur. Periorbital edema, bleeding from the combined membrane, and tearing are often accompanied by skin flushing. Auxiliary inspection

Coarse sieve test

Put a drop of the patient's urine on the filter paper, and then add azo P-nitroaniline diazo. If red, it indicates that 5-hydroxyindoleacetic acid (5-HIAA) is increased in the urine, which supports the disease. Diagnosis; if purple, it is a pheochromocytoma.

Determination of 5-HIAA in urine

Since 99% of 5-HT is converted into 5-HIAA in the body and excreted in the urine, measuring the total amount of 5-HIAA in the urine for 24 hours can help diagnose the disease. The total amount of 5-HIAA in the 24-hour urine of normal people is 10.5 to 42.0 mol. Most patients have urine 5-HIAA greater than 158 mol / 24 hours, and if it is greater than 263 mol / 24 hours, it has diagnostic value.

Determination of 5-HT in tumor tissue

The content of 5-HT in carcinoid tissues is significantly increased, which is more sensitive than the 5-HIAA method in urine. The use of ultrasound, CT, MRI, and ERCP examinations can help understand the location, size, and number of islet cell carcinoids, and provide localized diagnostic data for the formulation of a surgical plan.