A glucagonoma is a neuroendocrine tumor of the pancreas that produces the hormone glucagon, which raises the level of sugar (glucose) in the blood and causes a distinctive rash.
Glucagonomas arise from cells in the pancreas that produce glucagon.
Symptoms are similar to those caused by diabetes, including weight loss and excessive urination.
Diagnosis includes blood and imaging tests.
Treatment is surgery and sometimes chemotherapy.
Glucagon is a hormone normally secreted by the pancreas when blood glucose levels fall. Glucagon simulates the liver to break down stored carbohydrates to increase blood glucose.
Glucagonomas are a type of pancreatic neuroendocrine tumor. Most glucagonomas are cancerous (malignant). However, they grow slowly, and many people survive for 15 years or more after the diagnosis.
The average age at which symptoms begin is 50. About 80% of people with glucagonomas are women. A few people have multiple endocrine neoplasia.
Symptoms of Glucagonoma
High levels of glucagon in the blood cause the same symptoms as diabetes, such as weight loss and frequent urination.
In addition, many people with a glucagonoma have the very distinctive features of a chronic, brownish red rash (called necrolytic migratory erythema) and a smooth, shiny, bright red-orange tongue. In people with dark skin, flushing may cause reddening of the skin or increased darkening. The mouth also may have cracks at the corners. The rash, which causes scaling, starts in the groin and moves to the buttocks, forearms, hands, feet, and legs.
Diagnosis of Glucagonoma
Blood tests
Imaging tests
The diagnosis of glucagonoma is made by identifying high levels of glucagon in the blood.
Doctors then locate the tumor by doing computed tomography (CT) of the abdomen followed by endoscopic ultrasound. Magnetic resonance imaging (MRI) or positron emission tomography (PET) may be used if the CT scan does not show a tumor.
Treatment of Glucagonoma
Surgical removal
Sometimes chemotherapy
Octreotide or lanreotide
Ideally, the tumor is surgically removed, which eliminates all symptoms. However, if removal is not possible or if the tumor has spread, chemotherapy may be given. Chemotherapy may reduce the levels of glucagon and lessen the symptoms. However, chemotherapy has not been found to improve survival.
glucagon levels, may clear up the rash, and may restore appetite, facilitating weight gain. But octreotide and lanreotide may elevate the levels of glucose in the blood even more.
Zinc taken by mouth, applied in an ointment, or given by vein (intravenously) may also be used to treat the rash. Sometimes the rash is treated with intravenous amino acids or fatty acids.
