A spotlight on NENs - Types Archives - Ronny Allan - Living with Neuroendocrine Cancer

Category: A spotlight on NENs – Types

Neuroendocrine cells are found in almost every organ of the body and are also dispersed among other epithelial cells throughout the gastrointestinal and bronchopulmonary systems (the diffuse neuroendocrine system). The cells contain dense, core secretory granules, which synthesise, store and secrete serotonin and numerous other hormones/bioactive peptides with various functions in the gut, including nutrient sensing, gut secretions and motility, hormone release, and energy balance and appetite.

Neuroendocrine neoplasms (NENs) are uncommon tumours that derive from these neuroendocrine cells. They range in phenotype from poorly differentiated neuroendocrine carcinomas (NECs) to well-differentiated neuroendocrine tumours (NETs).

NENs (but mostly NETs) uniquely express cell-surface peptide hormone receptors, including somatostatin (SST) receptors (SSTRs). SST is a regulatory peptide hormone with a predominantly inhibitory function, inhibiting hormone secretion and cell proliferation and/or growth through five SSTR subtypes (SSTR1–5). The presence of SSTRs on NETs can be exploited to facilitate imaging and treatment of these tumours with somatostatin analogues (SSAs) and peptide-receptor radionuclide therapy (PRRT); and allow more detailed imaging output via SSTR PET.

26 Apr 2026

By Ronny Allan

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Spotlight on Small intestine Neuroendocrine Neoplasms (siNENs)

A spotlight on NENs, A spotlight on NENs - Types, Patient AdvocacyCarcinoid heart disease, Carcinoid syndrome, Hedinger syndrome, Ileum, Jejunum, Mesenteric Fibrosis, Retroperitoneal Fibrosis, Small intestine NET (SI NET), Terminal ileum

DisclaimerThis Spotlight is for general education and reassurance only. It cannot replace personalised advice from your own medical team, who understand your individual history, imaging, pathology, and treatment needs. Neuroendocrine tumours vary widely in behaviour, presentation, and management, and guidance may evolve as new evidence emerges. If you have questions about your diagnosis, symptoms, or treatment plan, please discuss them directly with your specialist NET team. Small intestine neuroendocrine neoplasms (siNENs) - (Jejunum + ileum — excluding duodenum) Small intestine neuroendocrine neoplasms (siNENs) arise in the mid‑gut, specifically the ileum and jejunum. These two segments form the core of “small intestine…

23 Apr 2026

By Ronny Allan

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A Spotlight on Pancreatic Neuroendocrine Neoplasms

A spotlight on NENs, A spotlight on NENs - Types, Patient AdvocacyATRX, DAXX, Gastrinoma, Gastro-entero-pancreatic neuroendocrine tumour (GEP-NET), Genetics, Glucagonoma, Insulinoma, MEN1 syndrome, Neurofibromatosis type 1 (NF1), Pancreatic NEC, Pancreatic NET (PanNET), PPoma, Somatostatinoma, Tuberous sclerosis (TSC), VIPoma, Von Hippel-Lindau (VHL) Syndrome

DisclaimerThe information in this Spotlight is for general education only. It cannot replace advice from your own medical team, who know your individual situation, test results, and treatment options. Neuroendocrine Neoplasms and related conditions are complex and research is evolving; guidance, classifications, and statistics may change over time. Always discuss any questions or concerns with your specialist team before making decisions about tests, treatments, or monitoring. Pancreatic neuroendocrine neoplasms comprise Pancreatic NETs (well differentiated) and Pancreatic NEC (poorly differentiated) 1. What they are Pancreatic NENs arise anywhere in the head, neck, body, or tail of the pancreas and include: Well‑differentiated…

03 Oct 2024

By Ronny Allan

5 Comments

A spotlight on Grade 3 (High grade) Neuroendocrine Neoplasms

A spotlight on NENs - Types, Awareness, Patient AdvocacyBlue Book, Differentiation, Grading, High grade neuroendocrine neoplasm (NEN), High grade neuroendocrine tumour (NET), Ki-67, Large cell neuroendocrine carcinoma (LCNEC), MANEC, Merkel cell carcinoma, Mixed Neuroendocrine Non-Neuroendocrine Neoplasms (MiNEN), Molecular markers, Neuroendocrine carcinoma (NEC), Neuroendocrine neoplasm (NEN), Neuroendocrine tumour (NET), Poorly differentiated, Small cell lung cancer (SCLC), Small cell neuroendocrine carcinoma (SCNEC), Somatostatin receptors (SSTR), Well differentiated

Reviewed and updated 3rd Jan 2025 High Grade Neuroendocrine Neoplasms - the forgotten patient group? When reading articles in the mainstream media, found in medical publications; and even listening to doctors speak about my disease, it's clear that the focus is on the term "Neuroendocrine Tumours" or NET for short. Many websites of advocate foundation organisations and specialist scientific organisations, all still use the term "NET" in their naming. I too am guilty of having a large Facebook site falling into this category. It's little wonder that those with high grade disease can often feel like the forgotten patient group. …

07 Jun 2023

By Ronny Allan

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A spotlight on duodenal Neuroendocrine Neoplasms (dNENs)

A spotlight on NENs - TypesAmpulla, Ampulla of Vater, Carcinoid syndrome, Duodenal NET (dNET), Duodenum, Gastrinoma, Hereditary pheochromocytoma/paraganglioma syndromes, Paraganglioma

What are Duodenal Neuroendocrine Neoplasms (dNEN)? The duodenum is technically part of the small intestine, and you can find that in most anatomy-based descriptions. One of the research references I used was titled "Somewhere between the pancreas and the small intestine" and in the case of Duodenal NENs (dNENs), I can understand why they adopted that unconventional anatomy description. I suspect they contextually meant that they are not like either of these organs, but they share some similarities. They are not normally treated like small intestine NETs (SI NETs) or pancreatic NETs (pNETs) but they share some relationships, particularly with…

12 May 2023

By Ronny Allan

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A spotlight on Rectal Neuroendocrine Neoplasms

A spotlight on NENs - Types, Awareness, Patient AdvocacyColorectal cancer, Rectal cancer, Rectal NET

What are Rectal NENs Rectal Neuroendocrine Neoplasms (NENs) (rNENs) account for approximately 1-2% of all primary cancers in the rectum. The other main cancer types found in the rectum are regular adenocarcinomas (the vast majority) and some other rare types including Gastrointestinal stromal tumors (GIST) and Lymphoma. The vast majority of rNENs will be well differentiated, i.e. rectal Neuroendocrine Tumours (rNETs) and are mostly indolent tumours treated effectively with surgical procedures if less than 1cm in size. Above that size there are different scenarios. Most will be found incidentally upon presentation of classic rectal symptoms or via colonoscopy screenings and…

26 Mar 2023

By Ronny Allan

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A spotlight on Appendiceal Neuroendocrine Neoplasms

A spotlight on NENs - Types, Awareness, Patient Advocacy, Spotlight on NENs - Types SeriesAppendectomy, Appendiceal NET, Appendix, Right hemicolectomy

What are Appendiceal NENs Appendiceal Neuroendocrine Neoplasms (NENs) account for approximately 60% of all primary cancers in the appendix. The other main cancer types found in the appendix are regular adenocarcinomas (including signet ring cell and goblet cell) and mucinous neoplasms such as Pseudomyxoma Peritonei (PMP) or Low-Grade Mucinous Neoplasms (LAMD). Appendiceal neuroendocrine tumours (aNET) (i.e. well differentiated) account for 75% of all aNENs, are mostly indolent tumours treated effectively with simple appendectomy. In fact, most are incidentally found upon presentation of right lower quadrant (RLQ) pain in keeping with appendicitis. They are typically (but not exclusively) diagnosed in younger…

22 Feb 2023

By Ronny Allan

2 Comments

A spotlight on Gastric Neuroendocrine Neoplasms (based on 2026 WHO Classification)

A spotlight on NENs - Types, Awareness, Patient Advocacy, Spotlight on NENs - Types Series, TreatmentAtrophic gastritis, Gastric NET, Gastrin, Gastrin pH, Gastrinoma, Hypergastrinemia, Neuroendocrine carcinoma (NEC), Neuroendocrine neoplasm (NEN), Neuroendocrine tumour (NET), Pernicious anaemia, Proton pump inhibitors (PPI)

What are Gastric NENs Unlike other anatomical types, the word Gastric is used to indicate a tumour (NET) or carcinoma (NEC) in the stomach. The stomach lies at the bottom of your oesophagus and connects to the first part of the small intestine (the duodenum). Clearly a key part of the gastrointestinal system, it processes food on its journey downwards. The stomach produces strong acid. This kills many microorganisms that might have been swallowed along with the food. It also contains special chemicals called enzymes. These are important for breaking down the food so it can be absorbed by the…

03 Mar 2022

By Ronny Allan

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A Spotlight on Lung Neuroendocrine Neoplasms

A spotlight on NENs - Types, Awareness, Patient Advocacy, Spotlight on NENs - Types SeriesAtypical carcinoid tumour, Atypical Lung NET, Combined Neuroendocrine Carcinoma, Cushing's syndrome, DIPNECH, Large cell neuroendocrine carcinoma (LCNEC), Lung NETs, MEN1 syndrome, Neuroendocrine carcinoma (NEC), Small cell lung cancer (SCLC), Syndrome of inappropriate antidiuretic hormone secretion (SIADH), Typical lung NET

WHO Classification of Tumours, 5th Edition, Volume 5: Thoracic Tumours The aim of this spotlight is to provide a summary of the latest information on Lung Neuroendocrine Neoplasms (NEN) including the latest terminology, epidemiology data, and guidelines. This follows the publication of the Thoracic WHO classification 5th edition (2021): terminology and criteria for neuroendocrine neoplasms (Blue Book). This book has been anticipated to see if the panel compiling this follows the lead of the Gastroenteropancreatic Neuroendocrine Neoplasms (GEPNEN) editions issued in 2017 (Endocrine) and 2019 (Digestive systems) by removing the antiquated misnomer term ''Carcinoid" in line with the recommendations made…

14 Dec 2016

By Ronny Allan

4 Comments

Neuroendocrine Tumours: a spotlight on Pheochromocytoma and Paraganglioma

A spotlight on NENs - Types, Awareness, Patient Advocacy, Spotlight on NENs - Types Series123I-Metaiodobenzylguanidine (mIBG), 131I-Metaiodobenzylguanidine (mIBG), 18F-FDG, 18F-FDOPA, 24-hour urinary catacholamines and metanephrines, Adrenal glands, Adrenal medulla, Adrenaline, Adrenocortical Carcinoma (ACC), Anxiety, AZEDRA, Catecholamines, EPAS1, Epinephrine, Familial NET, FH, Ga68 PET/CT, Genetics, Hormonal crisis, Hormones, Hyperadrenergic, Hypertension, Intraoperative hypertensive crisis, Iobenguane I 131, MDH2, MEN2 syndrome, MIBG scan, Multiple Endocrine Neoplasia (MEN), Nausea, Neuroendocrine, Neuroendocrine cancer, Neuroendocrine carcinoma (NEC), Neuroendocrine tumour (NET), NF1, Octreotide scan, Palpitation, Pheochromocytoma, RET, Scan, SDHA, SDHAF2(SDH5), SDHB, SDHC, SDHD, Somatostatin analogues, Surgery, Sweating, Tachycardia, The 5 E's, Vanillylmandelic acid (VMA), Von Hippel-Lindau (VHL) Syndrome

Updated 19th August 2025 I spend a lot of time talking about the most common forms of Neuroendocrine Tumours (NETs), but what about the less well-known types? As part of my commitment to all types of NETs, I'd like to shine a light on two less common tumour types known as Pheochromocytomas and Paragangliomas - with an incidence rate of approximately 8 per million per year. They are normally grouped together, and the definitions below will confirm why. If you think it's difficult to diagnose a mainstream NET, this particular sub-type is a real challenge. So, let's get definitions out…