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Health condition · Clinically reviewed

Carcinoid tumours, from DOTATATE PET to PRRT and specialist NET surgery.

Slow-growing but never straightforward. Modern NET care combines somatostatin analogues, targeted drugs, PRRT and complex surgery in a specialist MDT.

Jump to treatment
A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a UK NET specialist before publication.

  • 02

    Sourced from guidance

    Checked against ENETS, UKINETS, NCCN and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK NET practice including 68Ga-DOTATATE PET-CT, PRRT with 177Lu-DOTATATE and MDT care in ENETS Centres of Excellence.

Key facts

Carcinoid tumours at a glance.

The essentials, in plain English: where NETs arise, how they are graded and how modern UK care is put together.

  • What they are

    Well-differentiated neuroendocrine tumours (NETs) arising from neuroendocrine cells scattered throughout the gut, pancreas and lungs.

  • Where they arise

    Foregut (bronchial, thymic, gastric, duodenal, pancreatic), midgut (jejunum, ileum, appendix, proximal colon) and hindgut (distal colon, rectum). Midgut is the most common.

  • WHO 2019 grading

    Grade 1 (Ki-67 under 3%), grade 2 (3 to 20%) and grade 3 (over 20%), the last split into well-differentiated NET G3 and poorly differentiated neuroendocrine carcinoma (NEC).

  • Rising incidence

    Numbers are climbing, reflecting both better imaging and endoscopic detection and a genuine increase in cases.

  • Genetic overlap

    A minority sit inside inherited syndromes including MEN1, MEN2, VHL, NF1 and tuberous sclerosis. Genetic counselling matters.

  • Modern therapy

    Somatostatin analogues, PRRT with 177Lu-DOTATATE, targeted agents, liver-directed treatment and specialist surgery, all decided by a NET MDT.

Why this guide matters

A specialist MDT, not a generic plan.

NETs are uncommon, biologically varied and often long-lived. The three points below shape everything else on this page.

  • Grade drives everything

    Ki-67 sets the tempo. Grade 1 and 2 NETs behave very differently from NET G3 and poorly differentiated NEC, and the treatment ladders diverge.

  • Functional imaging is transformative

    68Ga-DOTATATE PET-CT finds disease conventional imaging misses and picks the patients who will benefit from PRRT.

  • Care belongs in a NET centre

    ENETS Centres of Excellence bring together the surgical, medical, radiological and nursing expertise needed to get this right first time.

How the diagnosis is made

From first suspicion to a settled plan.

The steps a UK NET MDT will normally follow, in order, so you know what to expect and why each test matters.

  1. 01

    Assessing

    History and symptom pattern

    Incidental finding, vague abdominal pain, weight loss, flushing or diarrhoea. The pattern often points to the primary site before any test is done.

  2. 02

    Assessing

    Biochemistry

    Chromogranin A for screening and monitoring (falsely raised on PPIs, in renal failure and atrophic gastritis), 24 hour urinary 5-HIAA for midgut and carcinoid syndrome, plus a hormone panel tailored to any functioning syndrome.

  3. 03

    Assessing

    Cross-sectional imaging

    CT chest, abdomen and pelvis with pancreatic protocol and MRI liver for metastases. This maps disease burden and resectability.

  4. 04

    Confirming

    Functional imaging

    68Ga-DOTATATE PET-CT is the gold standard for well-differentiated somatostatin receptor positive NETs. FDG-PET is added for high-grade, G3 and NEC disease. 111In-octreoscan is now largely historical.

  5. 05

    Confirming

    Endoscopy and biopsy

    EUS with FNA or biopsy for pancreatic and rectal primaries, colonoscopy for lower GI lesions and CT enteroclysis for small bowel disease. Tissue confirms the diagnosis.

  6. 06

    Preparing

    Pathology and immunohistochemistry

    Chromogranin, synaptophysin, CD56 and INSM1 confirm neuroendocrine origin. Ki-67 sets the grade and steers treatment intensity.

  7. 07

    Preparing

    Genetic counselling

    Consider testing for MEN1, MEN2, VHL, NF1 and tuberous sclerosis, particularly in younger patients or those with multiple primaries or a suggestive family history.

Typical timeline: first specialist review to MDT plan within a few weeks in a NET centre.

Symptoms

How carcinoid tumours actually present.

Many are silent until they are advanced. Others cause distinctive syndromes. The mix below shows the range you might meet in clinic.

  • Incidental finding

    A small bowel or appendiceal NET picked up at surgery or on imaging done for another reason. Very common in this disease.

  • Vague abdominal pain and bloating

    Non-specific symptoms are frequent. Persistent, unexplained abdominal discomfort with weight loss deserves imaging.

  • Diarrhoea and weight loss

    Loose stools that will not settle, sometimes with weight loss, can be an early clue to a midgut NET or a functioning syndrome.

  • Intestinal obstruction

    A mesenteric mass with kinking of small bowel loops can present with subacute or acute obstruction, often the first surgical clue.

  • Carcinoid syndrome

    Flushing, diarrhoea, bronchospasm and heart disease, usually with liver metastases or a bronchial or ovarian primary. See our carcinoid syndrome guide.

  • Functioning pancreatic NET

    Insulinoma (hypoglycaemia), gastrinoma (Zollinger-Ellison), glucagonoma (diabetes with a rash), VIPoma (WDHA syndrome) and rare somatostatinoma.

  • Non-functioning mass

    Non-functioning pancreatic or rectal NETs often present incidentally or with mass-effect symptoms rather than hormonal ones.

  • Red flag features

    Rapid weight loss, jaundice, obstruction, new hepatomegaly or refractory flushing all warrant urgent NET specialist input.

Treatment

How carcinoid tumours are treated in the UK.

A layered plan led by a NET MDT: curative surgery where possible, then somatostatin analogues, targeted therapy, PRRT and liver-directed treatment for advanced disease.

  • Curative surgical resection

    Bowel resection, distal or total pancreatectomy, Whipple procedure or hepatectomy in specialist HPB centres. The best chance of cure for localised disease.

  • Appendiceal NET surgery

    Appendicectomy alone for tumours under 2 cm without high-risk features. Right hemicolectomy for tumours over 2 cm, mesoappendix involvement, positive nodes or goblet cell histology.

  • Somatostatin analogues

    Octreotide LAR and lanreotide are first-line for advanced well-differentiated NETs. Control symptoms and slow tumour growth (PROMID and CLARINET trials).

  • Everolimus and sunitinib

    Everolimus (mTOR inhibitor) and sunitinib (VEGFR TKI) for progressive pancreatic NETs (RADIANT-3 and the sunitinib PROSPECT programme).

  • Telotristat ethyl

    For refractory carcinoid diarrhoea despite somatostatin analogues. See our telotristat ethyl clinic guide.

  • Liver-directed therapy

    TACE, TARE with Y90, RFA and microwave ablation for liver-dominant disease. Chosen in a NET MDT with interventional radiology.

  • PRRT with 177Lu-DOTATATE

    Practice-changing peptide receptor radionuclide therapy for progressive, well-differentiated, SSTR positive NETs (NETTER-1). Delivered in specialist UK NET centres.

  • Cytotoxic chemotherapy

    CAPTEM (capecitabine and temozolomide) or streptozotocin with 5-FU for pancreatic NETs. Etoposide with a platinum agent for NEC and high-grade disease.

What this guide is based on

The sources behind every claim on this page.

International NET society guidance and UK specialist standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your NET MDT knows your imaging, pathology and history and can tell you which parts apply to you. If in doubt, ask for a specialist opinion.

  • ENETS. Consensus guidelines for the management of gastroenteropancreatic and lung NETs.

  • UKINETS. UK and Ireland guidelines for neuroendocrine neoplasms.

  • NCCN. Neuroendocrine and adrenal tumors clinical practice guidelines.

  • NICE. Referral and management pathways relevant to neuroendocrine tumours.

  • WHO Classification of Tumours (2019). Digestive system tumours.

  • NETTER-1, PROMID, CLARINET, RADIANT-3 and CAPTEM trial evidence base.

Red flags

When a NET needs urgent attention.

Most surveillance is quiet and stable. These are the situations that are not, and where specialist input should be same-day or same-week.

  • Suspected carcinoid crisis

    Severe flushing, hypotension, arrhythmia or bronchospasm, particularly around anaesthesia or embolisation. A medical emergency needing IV octreotide and specialist care.

  • Bowel obstruction

    A mesenteric NET causing small bowel obstruction can present acutely. Persistent vomiting, distension and absent flatus need urgent surgical review.

  • Carcinoid heart disease

    Fatigue, breathlessness, ankle swelling or a new murmur in a patient with carcinoid syndrome warrants an urgent echocardiogram.

  • New jaundice

    A pancreatic head NET or bulky liver metastases can cause obstructive jaundice. This needs urgent imaging and hepatobiliary review.

  • Refractory hypoglycaemia

    Recurrent, unexplained hypoglycaemia should prompt insulinoma work-up, including a supervised 72 hour fast.

  • Zollinger-Ellison features

    Multiple, refractory or unusually sited peptic ulcers with diarrhoea should prompt fasting gastrin testing off PPIs and gastrinoma work-up.

  • Rapid clinical deterioration

    Rapid symptom change or FDG-avid disease can indicate transformation to a higher-grade NET or NEC and needs prompt reassessment.

  • Family history of endocrine tumours

    A personal or family history of pituitary, parathyroid, phaeochromocytoma or medullary thyroid cancer should prompt MEN1 or MEN2 testing.

  • Pregnancy planning

    Somatostatin analogues, PRRT and targeted agents all have specific pregnancy considerations. Plan ahead with the NET MDT.

Living with it

A long-term condition, with a clear team around you.

Four things that make the biggest difference year to year: the right team, regular monitoring, honest reporting of symptoms and access to the wider NET community.

A quiet reminder

A NET is a marathon, not a sprint.

Many people live well for many years. A steady partnership with a NET centre is worth more than a single dramatic intervention.

  1. 01 Team

    Insist on a NET MDT

    Outcomes are better when care is coordinated by a NET specialist centre with an oncologist, surgeon, radiologist, pathologist and specialist NET nurse.

  2. 02 Monitor

    Regular imaging and biochemistry

    Serial CT or MRI, 68Ga-DOTATATE PET-CT when indicated, chromogranin A and 5-HIAA give the earliest warning of change.

  3. 03 Symptoms

    Do not tolerate flushing or diarrhoea

    Symptom control is part of the plan, not a luxury. Somatostatin analogues and telotristat can transform daily life.

  4. 04 Support

    Use the NET patient community

    Neuroendocrine Cancer UK and the NET Patient Foundation offer practical information, peer support and links to specialist centres.

Frequently asked

Everything we get asked about NETs.

Quick answers on grading, imaging, PRRT, inherited risk and where care belongs.

  • What is a carcinoid tumour?

    A carcinoid tumour is an older term for a well-differentiated neuroendocrine tumour (NET) that arises from neuroendocrine cells in the gut, pancreas or lungs. Most are slow-growing but they can spread, particularly to the liver, and some produce hormones that cause distinctive syndromes.

  • How is the grade decided?

    Pathologists use the WHO 2019 system based on the Ki-67 proliferation index. Grade 1 tumours have a Ki-67 below 3%, grade 2 between 3 and 20% and grade 3 above 20%. Grade 3 is split into well-differentiated NET G3 and poorly differentiated neuroendocrine carcinoma (NEC), which behave very differently.

  • Which scans are used to stage a NET?

    CT of the chest, abdomen and pelvis with a pancreatic protocol and MRI of the liver are standard for anatomy. 68Ga-DOTATATE PET-CT is the gold standard functional scan for well-differentiated NETs. FDG-PET is added for higher-grade or aggressive disease.

  • What is PRRT and who is it for?

    PRRT is peptide receptor radionuclide therapy, most commonly with 177Lu-DOTATATE (Lutathera). It targets somatostatin receptors on well-differentiated NETs and has changed practice for progressive, SSTR positive disease. It is delivered at specialist UK NET centres including Royal Free, Christie, University College, Newcastle, Sheffield, Basingstoke and Liverpool.

  • Do carcinoid tumours run in families?

    Most are sporadic, but a minority sit inside inherited syndromes including MEN1, MEN2, VHL, NF1 and tuberous sclerosis. A personal or family history of pituitary, parathyroid, phaeochromocytoma or medullary thyroid cancer should trigger genetic counselling and testing.

  • Where should I be treated?

    Care should be led by a NET MDT at a specialist centre with access to modern imaging, PRRT, complex HPB surgery, interventional radiology and specialist NET nursing. Neuroendocrine Cancer UK can help you find your nearest ENETS Centre of Excellence.

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