Insulinomas are the most common pancreatic endocrine tumor.
Insulinoma is a tumor of the pancreas that produces too much amounts of insulin. High insulin levels cause low blood sugar levels (hypoglycemia). Hypoglycemia may be gentle, leading to symptoms such as anxiety and hunger, or severe, leading to seizures, coma, and even death. Insulinomas are more common in women. The tumors are usually tiny and more than 90% of all insulinomas are benign. Insulinomas produce extreme amounts of insulin and this causes low blood sugar. Most insulinomas are kindly only 5 to 10 percent are cancerous.
They are very uncommon in children. Most children with hyperinsulinism have many areas of overactive insulin-secreting cells in the pancreas, fairly than a single tumor. Symptoms of insulinoma may comprise dizziness, disorientation and weight gain often patients feel better after they eat, and so eat more frequently. Other symptoms of the lack of food to the brain results in the signs seen which usually are periodic. The early signs are: depression, lethargy, blankly staring with poor response to sound or touch, salivating and pawing at the mouth, and periodic weakness, especially of the hind quarters.
Sometimes inflamed spleens are seen. More severe signs are stupors, seizures, severe weakness, and coma. The cause of most insulinomas is linked with an inherited condition, called MEN1 (multiple endocrine neoplasia 1), where tumors can arise in a number of hormone-producing glands. Surgery is the normal treatment for insulinoma. The tumor is localized with diagnostic testing or surgical exploration. Solitary tumors are removed, but patients with multiple tumors usually need partial removal of the pancreas (partial pancreatectomy). At least 15% of the pancreas is left to avoid malabsorption due to lack of pancreatic enzymes.
If no tumor is found at surgery or a patient is not an applicant for surgery, the drug diazoxide may be given to lower insulin secretion and shun hypoglycemia. A diuretic is always given with this medication to avoid retaining too much salt. Medical treatment is also used to stabilize the person prior to surgery. Medications such as diazoxide and somatostatin can be used to block the release of insulin for patients who are not surgical candidates or who otherwise have inoperable tumours. Streptozotocin is used in islet cell carcinomas which produce too much insulin. Octreotide has also been used to suppress insulin secretion in some patients.
