Neuroendocrine tumours (NETs)

GI NETs start in organs in the gastrointestinal (GI) system. This includes the small bowel (small intestine), back passage (rectum), stomach, colon, oesophagus and appendix. GI NETs are a common type of NET. Most GI NETs grow slowly. Symptoms include:

• Diarrhoea
• Constipation
• Nausea
• Vomiting
• Bleeding from the rectum
• Fatigue
• Weight loss
• Tummy pains
• Blockage in the intestine

Carcinoid syndrome is a group of symptoms caused by a NET releasing large amounts of a hormone-like substance called serotonin or other chemicals into the blood. 

Most patients with a NET do not have carcinoid syndrome. It is most common with small bowel NETs but it can happen with other types of NETs.  The signs or symptoms of carcinoid syndrome include:

• Flushing (hot and reddened) skin, mainly in the face and upper chest area
• Diarrhoea
• Breathing difficulties, wheezing
• Fast or irregular heartbeat
• Low blood pressure
• Heart damage (carcinoid heart disease)

Carcinoid crisis is a severe case of carcinoid syndrome symptoms such as flushing, low blood pressure, breathing difficulties and palpitations. Having a general anaesthetic, surgery or other treatments can trigger a carcinoid crisis. Carcinoid crisis is serious and may be life-threatening. Your medical team will take extra precautions to avoid this if you are having treatment. A drug called octreotide (Sandostatin) can be given to treat and reduce the risk of carcinoid crisis.

Carry the card

Click here for a carcinoid crisis card that you can print and carry with you to let doctors and other people know you’re a NET patient who may need Octreotide infusions in urgent or emergency circumstances.

• Coughing up blood
• Wheezing
• A persistent cough
• Difficulty breathing
• Pneumonia
• Fatigue (extreme tiredness)

Lung and pancreatic NETs can cause too much of the hormone cortisol to be produced. This can cause a collection of symptoms called Cushing syndrome.This is rare and causes symptoms such as:

• Weight gain – including between the shoulders, around your middle and above the collar bone
• A round, red face (moon face)
• Pink or purple stretch-mark like lines on the skin
• Muscle weakness
• Increased hair on the face and body
• High blood pressure
• High blood sugar levels
• Changes in mood and behaviour changes, e.g. depression, anxiety and irritability

• Sweating, shaking, dizziness, heart palpitations, hunger and forgetfulness and confusion (caused by low blood sugar levels - hypoglycaemia)
• Extreme thirst, needing to urinate a lot,  diarrhoea and greasy bowel movements (caused by high blood sugar levels - hyperglycaemia)
• Heartburn, indigestion and pain in the chest or tummy (caused by stomach ulcers)
• Weight loss
• Rashes
• Yellowing of the skin and the whites of the eyes (jaundice)
• Blood clots
• Cushing syndrome – see above

The symptoms depend mainly on the type of hormone released by the tumour.

Some types of NETs of the pancreas or small intestine (gastrinoma) may cause a set of symptoms called Zollinger-Ellison syndrome. The symptoms include:

• Severe diarrhoea
• Tummy pain
• Heartburn
• Nausea and vomiting, sometimes vomiting blood
• Weight loss