Health condition
Neuroendocrine carcinoma high grade
High-grade neuroendocrine carcinomas are aggressive cancers biologically akin to small cell lung cancer, arising anywhere in the body; they demand rapid platinum-etoposide chemotherapy and are distinct from the slower-growing neuroendocrine tumours they are often confused with.
Why trust this guide
- 01
Editorial team
Written by our editorial team from the UK sources listed on each page.
- 02
Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
- 03
Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
-
Defined by high proliferation (Ki-67 above 20%, usually far higher) and small or large cell morphology
-
Completely different from low-grade NETs - the words sound alike, the diseases are not
-
Platinum-etoposide chemotherapy, started promptly, is the standard first-line treatment
-
Expert pathology review is critical, since grade determines the entire strategy
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
The neuroendocrine family spans a chasm: at one end, well-differentiated tumours that smoulder for years; at the other, poorly differentiated carcinomas that double in weeks. High-grade disease - small cell or large cell types - arises in lung, gut, pancreas, bladder, cervix or without an obvious primary, presents with rapid symptoms, and behaves systemically from the outset. The Ki-67 index and differentiation on biopsy, read by pathologists versed in this classification, carry the full weight of the treatment decision.
Diagnosis and treatment routes
Treatment mirrors small cell lung cancer logic: prompt platinum-etoposide chemotherapy, to which responses are often rapid and substantial, with radiotherapy consolidating limited disease and surgery reserved for genuinely localised cases. Relapse tends to come early, so trial options and second-line regimens are mapped in advance. A distinct middle group - well-differentiated grade 3 NETs - responds differently and is worth explicitly distinguishing at MDT, another argument for specialist review of the pathology. If you are waiting for results or want a second opinion on a proposed plan, a private consultation with a specialist who treats this condition regularly can usually be arranged quickly, and most will review your existing scans, biopsy reports and MDT correspondence.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant oncologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.
Frequently asked
Common questions about Neuroendocrine carcinoma high grade.
Quick, plain-English answers to what people ask us most.
-
What is high-grade neuroendocrine carcinoma?
High-grade neuroendocrine carcinoma is an aggressive type of neuroendocrine cancer with rapidly dividing cells, behaving more like other fast-growing cancers than the typically slower-growing neuroendocrine tumours.
-
What causes high-grade neuroendocrine carcinoma?
As with most cancers, the exact trigger for the abnormal cell changes isn't always identifiable, though it arises from neuroendocrine cells located throughout the body, most commonly in the lungs or gastrointestinal tract.
-
What are the symptoms of high-grade neuroendocrine carcinoma?
Symptoms depend on the tumour's location but often include those related to the primary site, such as cough or abdominal pain, alongside general cancer symptoms like weight loss and fatigue, and sometimes symptoms from hormone secretion.
-
Is high-grade neuroendocrine carcinoma dangerous?
Yes, it's an aggressive cancer that tends to grow and spread more quickly than lower-grade neuroendocrine tumours, generally requiring prompt, intensive treatment similar to other aggressive cancers.
-
How is high-grade neuroendocrine carcinoma treated?
Treatment typically involves chemotherapy as the primary treatment, given the cancer's aggressive, fast-growing nature, sometimes combined with surgery or radiotherapy depending on the extent and location of disease.
-
When should I see a specialist about suspected high-grade neuroendocrine carcinoma, and how quickly can I be seen privately?
Seek prompt oncology assessment for concerning symptoms with suspicious imaging findings. A private oncologist can typically arrange urgent assessment within about one week given the aggressive nature of this cancer.