The patient recovered uneventfully with the glucagonoma syndrome disappeared soon after surgery, and the postoperative plasma glucagon decreased to a normal level.
Accurate measurement of glucagon has been essential for uncovering its pathological hypersecretion that underlies various metabolic diseases including not only diabetes and liver diseases but also cancers (glucagonomas).
Subsequently, the pancreatic lesion was excised, and pathology assessment confirmed the diagnosis of well-differentiated neuroendocrine tumour with high expression of glucagon compatible with glucagonoma.
In patients with glucagon-producing tumors (glucagonomas), the most conspicuous signs are skin lesions (necrolytic migratory erythema), while in subjects with inactivating mutations of the glucagon receptor, pancreatic swelling may be the first sign; neither condition is necessarily associated with disturbed glucose metabolism.
Both primary and metastatic tumors express high levels of glucagon; furthermore, an increased level of glucagon is found in the serum, identifying the pancreatic cancer as a functional glucagonoma.
The glucagon receptor (GCGR) gene and the glucagon gene were sequenced in a patient with hyperglucagonemia and pancreatic alpha cell hyperplasia without glucagonoma syndrome.
Glucagon-producing tumors are either solitary neoplasms of the pancreas, occasionally associated with a glucagonoma syndrome, or multiple neoplasms associated with multiple endocrine neoplasia type 1 (MEN1).
Whereas extracts of human pancreas and a glucagonoma contained a large proglucagon cleavage product possessing both GLP-1 and GLP-2 immunoreactivities, extracts of human intestine contained products corresponding to free GLP-1 and a small amount of chromatographically distinct GLP-2 immunoreactivity.