Glucagonoma is a rare, functioning type of pancreatic neuroendocrine tumor (PNET; see this term) that hypersecretes glucagon, leading to a syndrome comprised of necrolytic migratory erythema, diabetes mellitus, anemia, weight loss, mucosal abnormalities, thromboembolism, gastrointestinal and neuropsychiatric symptoms.

An endocrine tumor arising from an APUD cell.