5-hydroxyindoleacetic acid (5-HIAA): a reliable, 24-hour urine test that is specific to carcinoid tumours. With this test, 5-hydroxyindoleacetic acid (5-HIAA) is measured in the urine. 5-HIAA is a metabolite of serotonin, a natural chemical messenger that is overproduced in people with GEP NE tumours

Acromegaly: a condition characterized by enlarged features; caused by overproduction of growth hormone and insulin-like growth factor-I

Adenoma: a type of noncancerous tumour

Amine: member of a group of chemical compounds formed from ammonia by replacement of one or more of the hydrogen atoms

Carcinoid tumour: the most common GEP NE tumour; arises from neuroendocrine cells; primarily occurs in the appendix, ileum, rectum, and bronchus

Carcinoid syndrome: the most common systemic clinical manifestation of carcinoid tumours; usually develops after a carcinoid tumour has metastasised, usually to the liver, and there is a substantial concentration of the hormones released by a tumour in the systemic circulation

Chromogranin A (CgA) Testing: a fast, easy blood test for testing all major types of GEP NE tumours

Gastrin: a polypeptide hormone that is released for G cells in the pyloric glands in the gastric antrum and peptidergic fibers in the vagus nerve

Gastrinoma: a gastrin-releasing islet cell tumour that is associated with Zollinger-Ellison syndrome

Gastro-entero-pancreatic (GEP) neuroendocrine (NE) tumours: tumours of the gut and pancreas that can result in hypersecretion of a variety of hormones and other substances depending on the location of the tumour

Glucagonoma: a glucagon-releasing islet cell tumour located in the body or tail of the pancreas

Growth hormone (GH): released by the pituitary gland and stimulates growth throughout the body

Growth hormone-releasing hormone (GHRH): hypothalamic factor that stimulates the pituitary to make growth hormone

Hepatic embolization: procedure that reduces blood flow to the liver in an attempt to kill a tumour

Hypoglycaemic syndrome: associated with insulinomas, which secrete an excess amount of insulin.

Insulin-like growth factor-I (IGF-I): a hormone that causes bone and tissue growth; is produced in the liver when secretion of GH from the pituitary gland occurs; IGF-I signals the pituitary to reduce GH production

Insulinoma: an islet cell tumour that secretes excess insulin, and may occasionally secrete other hormones, including gastrin, ACTH, and glucagon

OctreoScan^® Somatostatin Receptor Scintigraphy (SRS) Testing: a highly accurate and versatile imaging test for all of the body's systems

Octreotide: the synthetic analogue of somatostatin, used to treat certain conditions such as acromegaly and hypersecretion from GEP NE tumours

Peptide: a member of a class of low-molecular-weight compounds that yields two or more amino acids on hydrolysis

Serotonin: a monoamine vasocontrictor that has many physiologic properties in the body

Somatostatin: a native hormone that inhibits several endocrine functions

Vasoactive intestinal peptide tumour (VIPoma): an islet cell tumour that secretes an excess of VIP, a 28-amino acid peptide; in the gastrointestinal tract VIP plays a role in water transport and as a local neurotransmitter and modulating ion; it also plays a role in vascular tone

Verner-Morrison syndrome: synonymous with VIPomas

Zollinger-Ellison syndrome: synonymous with gastrinomas