Insulinoma

Insulinoma
Pathology of pancreatic endocrine tumour (insulinoma).
SpecialtyOncology

An insulinoma is a tumour of the pancreas that is derived from beta cells and secretes insulin. It is a rare form of a neuroendocrine tumour. Most insulinomas are benign in that they grow exclusively at their origin within the pancreas, but a minority metastasize. Insulinomas are one of the functional pancreatic neuroendocrine tumour (PNET) group ("functional" because it increases production of insulin).[1] In the Medical Subject Headings classification, insulinoma is the only subtype of "islet cell adenoma".[2]

Beta cells secrete insulin in response to increases in blood glucose. The resulting increase in insulin acts to lower blood glucose back to normal levels, the point at which further secretion of insulin is stopped. In contrast, the secretion of insulin by insulinomas is rather independent of blood glucose; these tumours continue to secrete insulin, causing blood glucose levels to fall further below normal.[3]

As a result, patients present symptoms of low blood glucose (hypoglycemia), which are improved by eating. The diagnosis of an insulinoma is usually made biochemically with low blood glucose, elevated insulin, proinsulin, and C-peptide levels, and confirmed by localizing the tumour with medical imaging or angiography. The definitive treatment is surgery.[3]

  1. ^ Burns, William R.; Edil, Barish H. (March 2012). "Neuroendocrine Pancreatic Tumors: Guidelines for Management and Update". Current Treatment Options in Oncology. 13 (1): 24–34. doi:10.1007/s11864-011-0172-2. PMID 22198808. S2CID 7329783.
  2. ^ MeSH website, tree at: "Pancreatic Neoplasms [C04.588.322.475]",[dead link] accessed 16 October 2014
  3. ^ a b "Insulinomas". The Lecturio Medical Concept Library. Retrieved 27 July 2021.