Overview
A glucagonoma is a rare neuroendocrine tumor that originates almost exclusively in the pancreas and probably accounts for 1% of all neuroendocrine tumors. Malignant glucagonomas are islet cell pancreatic tumors that are discovered because of glucagonoma syndrome (in which the glucagonoma autonomously secretes glucagon), because of local mass effects, or incidentally. Glucagonomas originate from the alpha-2 cells of the pancreas. Unregulated production (overproduction) of peptide hormones and growth factors, which are not normally expressed in the tissue of origin, is characteristic of neuroendocrine tumors. Abnormal production of these bioactive peptides can lead to significant systemic toxic consequences and to the promotion of further tumor growth.
In 75-80% of cases, the glucagonoma starts in malignant form, and in 50% of these cases, metastasis exists at diagnosis. The tumor's presence is characterized by glucagon overproduction, weight loss, hyperglycemia, diabetes mellitus, hypoaminoacidemia, normochromic and normocytic anemia, and necrolytic migratory erythema (NME), which is the most characteristic clinical sign (as opposed to symptom) of this pathology