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.

The presence of chronic diarrhea, which is usually taken to mean diarrhea that has persisted for over 4 weeks.