Clinical use
Diagnosis and subsequent monitoring of a diverse group of neuroendocrine tumours that arise from the endocrine and nervous systems.
Background
Neuroendocrine tumours (NETs) are a group of tumours that can be a challenge to diagnose. Common features are similar morphology, presence of secretory granules and the production of biogenic amines and polypeptide hormones. Prevalence is about 35:100,000 of which two-thirds are carcinoid tumours. Certain NETs can produce vague, nonspecific symptoms (such as diarrhoea, abdominal pain, flushing, and hypoglycaemia) that are easily mistaken for other conditions, such as irritable bowel syndrome and inflammatory bowel disease.
NETs can form in multiple locations throughout the body, including difficult-to-pinpoint areas within the midgut. It is not unusual for patients to suffer for years before a NET is correctly diagnosed. The majority of NETs originate in the gastrointestinal tract or pancreas, and are collectively referred to as gastroenteropancreatic NETs (GEP-NETs). There are several different types of GEP tumours (gastroenteropancreatic tumours). They tend to develop in the organs of the digestive system such as the stomach, intestines and the pancreas. NETs that are not gastrointestinal or pancreatic in origin
can arise in the respiratory tract, ovaries, and testes, as well as in other endocrine tissue (e.g., thymus, adrenal gland). Also included in the NET classification are some inherited conditions including Multiple Endocrine Neoplasia type 1 (MEN1), MEN2, neurofibromatosis and Von-Hippel-Lindau (VHL) disease
Reference ranges
| Test | Reference range |
|---|---|
| Chromagranin A | <102 µg/L |
| Pancreatic polypeptide | <300 pmol/L |
| Somatostatin | <150 pmol/L |
| Gastrin | <40 pmol/L |
| Glucagon | <50 pmol/L |
| Vasoactive intestinal peptide | <30 pmol/L |
Patient preparation
Patient should be fasted overnight and off proton pump inhibitors for 3 days if under investigation for a suspected gastrinoma.
Specimen requirements
2 full EDTA (purple top) tubes and 1 SST (yellow top) tube (if Chromagranin A is required)
Minimum volume
3ml per tube
Limitations/Restrictions
EDTA samples should be received on ice within 30 minutes of collection.
Turnaround time
- Fasting gut hormone profile (Imperial): 6 weeks
- Chromogranin A (RVI): 3 weeks
Analysing laboratory
Fasting gut hormone profile: SAS Endocrine Laboratory Clinical Biochemistry, 8th Floor, Charing Cross Hospital, Imperial College NHS Healthcare Trust, Fulham Palace Road, London, W6 8RF
Chromogranin A: Blood Sciences, Level 3, Leazes Wing, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP