Insulinom

The insulinoma is a rare pancreatic ?-cell tumor, the hypersecreted insulin. The main symptom is a Nüchternhypoglykämie. The diagnosis is made of glucose and insulin levels during determination of a 48-H or 72-hour fasting test, followed by an endoscopic ultrasonography. Whenever possible, treatment should be done surgically. Drugs that inhibit insulin secretion (z. B. diazoxide, octreotide, calcium channel blockers, beta-blockers, phenytoin), are used in patients who do not respond to surgical treatment.

The insulinoma is an endocrine pancreatic tumor (Endocrine pancreatic tumors), which develops from islet cells. 80% of all insulinomas are solitary and can – if they are identified – may be curative resection. Only 10% of insulinomas are malignant. The incidence of insulinomas is 1: 250,000, the median age at 50 years, an exception exists within the syndrome of multiple endocrine neoplasia (MEN, multiple endocrine neoplasia overview) Type 1 (about 10% of insulinomas), there occurs there in the 20s on. With MEN 1 Associate Insulinomas have a higher probability of multiple occur.

The insulinoma is a rare pancreatic ?-cell tumor, the hypersecreted insulin. The main symptom is a Nüchternhypoglykämie. The diagnosis is made of glucose and insulin levels during determination of a 48-H or 72-hour fasting test, followed by an endoscopic ultrasonography. Whenever possible, treatment should be done surgically. Drugs that inhibit insulin secretion (z. B. diazoxide, octreotide, calcium channel blockers, beta-blockers, phenytoin), are used in patients who do not respond to surgical treatment. The insulinoma is an endocrine pancreatic tumor (Endocrine pancreatic tumors), which develops from islet cells. 80% of all insulinomas are solitary and can – if they are identified – may be curative resection. Only 10% of insulinomas are malignant. The incidence of insulinomas is 1: 250,000, the median age at 50 years, an exception exists within the syndrome of multiple endocrine neoplasia (MEN, multiple endocrine neoplasia overview) Type 1 (about 10% of insulinomas), there occurs there in the 20s on. With MEN 1 Associate Insulinomas have a higher probability of multiple occur. An artificial application of exogenous insulin can cause episodic hypoglycemia mimicking insulinoma. Symptoms and complaints by insulinoma induced hypoglycemia occur during fasting. Symptoms are confusing and can mimic various psychiatric and neurological diseases. Under certain circumstances occurring CNS disorders include headache, confusion, blurred vision, motor weakness, paralysis, ataxia, significant personality changes and a Moegli-che progression to loss of consciousness, seizures and coma. Symptoms of sympathetic stimulation (fatigue, weakness, tremors, palpitations, sweating, hunger and nervousness) are often present. Diagnosis Sometimes insulin C-peptide or proinsulin Endoscopic Ultrasound The plasma glucose should be measured during the occurrence of symptoms. When a hypoglycaemia (glucose <40 mg / dL [2.78 mmol / l]), the insulin level should be determined in the same sample. Hyperinsulinemia of> 6 uU / ml (42 pmol / l) indicates a mediated insulin cause, as well as a ratio of serum insulin-to plasma glucose> 0.3 (uU / ml) / (mg / dl). Insulin is secreted as proinsulin, this consists of an ?- and a ?-chain, which are connected by a C-peptide. Since pharmaceutical insulin consists only of the ? chain, an artificial application of insulin can be detected by determining the levels of C-peptide and proinsulin. In patients with insulinoma the C-peptide levels are at ? 0.2 nmol / l and the proinsulin at ? 5 pmol / l. These levels are normal or low in patients with artificial insulin administration. Since many patients have no symptoms at the time of the evaluation (and therefore no hypoglycemia), the diagnosis requires hospitalization for a 48-h or 72-hour fasting test. Almost all (98%) patients with insulinoma develop symptoms within a 48-hour fasting period, 70-80% already within 24 hours. Hypoglycemia as a cause of the symptoms is demonstrated by the presence of Whipple’s triad: 1. the symptoms occur during fasting; 2. the symptoms occur during the presence of hypoglycemia; 3. intake of carbohydrates reduces the symptoms. The hormone levels are determined as described above, when symptoms appear in the patient. If the Whipple’s triad is not observed even after prolonged fasting and the plasma glucose levels after an overnight fast at> 50 mg / dl (> 2.78 mmol / L), a C-peptide suppression can be performed. While an insulin infusion (0.1 U / kg / h) is suppressed in patients with insulinoma the C-peptide levels to normal values ??(? 1.2 ng / ml [? 0.40 nmol / l]). The endoscopic ultrasonography has a sensitivity of> 90% and helps to localize the tumor. PET can also be used. The CT has not proved to be useful and an angiography or selective catheterization of portal vein and splenic vein is generally not necessary. Therapy Surgical resection diazoxide or occasionally octreotide in chemotherapy hypoglycemia Total operative therapies achieve cure rates of up to 90%. A small, solitary insulinoma at or near the pancreas surface can usually be enucleated by the surgeon. If find a solitary large or deep adenoma in the field of pancreatic body or tail of present or multiple lesions in body or tail (or both) or no insulinoma can be found (an unusual circumstance) is performed a distal, subtotal pancreatectomy. In <1% of cases insulinoma is located ectopically in peripancreatic tissues of the duodenal wall or the periduodenalen tissue and can only be found through sorgfältigeste intraoperative search. A Pancreaticoduodenectomy (Whipple procedure) is carried out at resectable malignant insulinomas of the proximal pancreas. A complete pancreatectomy is performed when a previous partial pancreatectomy showed insufficient. When the hypoglycemia persists, diazoxide can (n. D. Übers .: a strongly diabetogenic thiazide diuretic) initially with 1.5 mg / kg p.o. 2 times a day with a natriuretic (n. D. Übers .: diazoxidinduzierten because of sodium retention) are added. The dose may be increased up to 4 mg / kg. The somatostatin analogue octreotide (100-500 ug s.c. 2 to 3 times daily) is different effective and should be considered in patients with continued, diazoxidrefraktärer hypoglycemia. Responsively patients can be converted to a long-acting Octreotidpräparat (20-30 mg i.m. once a month). Patients often have to take additional Octreotidmedikation pancreatic enzymes because octreotide inhibits the secretion of pancreatic enzymes. Other substances that have a modest and variable effect on insulin secretion, are Verapamil, Diltiazem and phenytoin. If the symptoms are not controlled, chemotherapy can be attempted, but the response rates are limited. Streptozotocin has a response rate of 30-40% and in combination with 5-fluorouracil a response rate of 60%, which can last up to 2 years. Other substances are doxorubicin, chlorozotocin and interferon. Newer chemotherapies that are studied in insulinoma include temozolomide-based regime, everolimus or sunitinib. Important points Only about 10% of insulinomas are malignant, but all cause Nüchternhypoglykämie. In the presence of symptoms (either spontaneous or induced by fasting during hospitalization) glucose and insulin levels are measured. The endoscopic ultrasonography has a sensitivity> 90% in the localization of the tumor; PET can also be used, however, a CT is not useful. About 90% of insulinomas can be surgically resected. The symptoms of hypoglycemia can be personalized with diazoxide or sometimes octreotide control.

Health Life Media Team

Leave a Reply