CION Ameerpet
Pancreatic Cancer · Neuroendocrine Tumours (PNET) · Reviewed by CION Oncologists
Functioning vs non-functioning PNETs — what the label actually changes
One kind of pancreatic neuroendocrine tumour releases a hormone and announces itself through symptoms. The other releases nothing and is usually found on a scan. Here is what that difference genuinely changes about your tests, your treatment and your follow-up — and what it does not.
- “Non-functioning” does not mean harmless — it means the tumour is not producing a hormone syndrome.
- Grade and stage drive the plan — hormone status adds a second job, it does not replace the first.
- Functioning tumours are often found small — the hormone gives them away before the size does.
- Both are treated on the neuroendocrine track — not on the pathway used for ductal adenocarcinoma.
17+
Cancer Specialists
on Panel
on Panel
35+
Centres Across
Telangana & AP
Telangana & AP
15,000+
Patients
Treated
Treated
4.8★
Google Rating
(800+ reviews)
(800+ reviews)
Start here
What “Functioning” Actually Means
Pancreatic neuroendocrine tumours grow from the hormone-producing islet cells scattered through the pancreas, not from the duct lining where the far more common ductal adenocarcinoma begins. That single difference in origin is why the hormone question arises at all. A functioning PNET releases an active hormone in enough quantity to produce a recognisable pattern of symptoms. A non-functioning PNET either makes no active hormone, or makes so little that nothing shows up clinically.
The wording misleads people, and it is worth correcting straight away. “Non-functioning” does not mean inactive, harmless or slow. It means the tumour is not announcing itself through a hormone. Most pancreatic neuroendocrine tumours fall into this group, and because there is no hormone syndrome to raise the alarm, they are more often found later — either by chance on a scan done for something else, or once the tumour is large enough to press on nearby structures and cause abdominal or back pain, jaundice or weight loss.
A functioning tumour, by contrast, often declares itself while it is still small. The symptoms come from the hormone rather than from the tumour's bulk, so people are frequently investigated for months for what looks like a metabolic, gastric or skin problem before the pancreas is suspected at all. Being found early because of a hormone is a real advantage; the delay in connecting the symptoms to a cause is the part that frustrates most patients afterwards.
Both groups sit inside the same disease family, and the general picture — how these tumours behave, how they are staged and why they are treated on a different track from adenocarcinoma — is set out in pancreatic neuroendocrine tumours (PNET) explained. This page stays with one question only: what the functioning label changes, and what it does not.
Did you know? Under the WHO classification of neuroendocrine neoplasms, a pancreatic tumour is graded on how the cells look and how quickly they are dividing — well-differentiated neuroendocrine tumours are separated into grade 1, grade 2 and grade 3, and are kept distinct from poorly differentiated neuroendocrine carcinoma. Whether the tumour secretes a hormone is recorded separately and forms no part of that grade. NCCN guidance follows the same logic: functioning and non-functioning tumours are staged and graded on one common framework, with hormone control added on top for the functioning ones. In other words, the label tells your team which symptoms to manage, while grade and stage tell them how the tumour is likely to behave.
Side by side
Where the Two Genuinely Differ — and Where They Do Not
The last two rows matter most. People assume the label changes everything; in practice it changes one part of the plan and leaves the rest untouched.
| What is compared | Functioning PNET | Non-functioning PNET |
|---|---|---|
| How it comes to light | Through the hormone. A repeating pattern of symptoms is investigated, often for a long time, before the pancreas is suspected. | Through the tumour itself, or by chance. Found incidentally on a scan, or once it is large enough to cause pain, jaundice or weight loss. |
| Typical first symptoms | Depend entirely on which hormone: low blood sugar episodes, stubborn ulcers and reflux, watery diarrhoea, a spreading rash, or blood sugar that has become hard to control. | Often none for a long period. Later, vague upper abdominal or back pain, fullness after small meals, and jaundice if the bile duct becomes involved. |
| Bloods that matter | Targeted hormone measurement under carefully controlled conditions, because timing and preparation change the result. | General neuroendocrine markers and routine bloods. There is no hormone level to follow, so imaging carries more of the weight. |
| Size when found | Frequently small, because the hormone gives the tumour away long before its size would. | Often larger at diagnosis, simply because nothing prompted a scan any sooner. |
| What the label changes | Adds a second job to the plan: controlling the hormone effects promptly, so you are safe and comfortable while the tumour itself is dealt with. | Nothing extra to control. The plan concentrates from the outset on the tumour, its grade and whether it can be removed. |
| What it does not change | Grade, stage and whether the tumour can be removed drive the outlook and the treatment sequence in both groups. Systemic options are chosen on grade and spread, not on hormone status — see pancreatic cancer treatment in Hyderabad. | |
If yours is functioning
The Hormone Syndromes That Are Recognised
Each is named after the hormone the tumour releases. Having one of these symptom patterns does not mean you have a PNET — every one of them has far commoner explanations. It means the pattern is worth explaining properly rather than treating piecemeal.
Insulinoma
Repeated low blood sugar
Sweating, confusion, shakiness or faintness that eases after eating, often worst before breakfast. The commonest functioning PNET, and usually small when found — insulinoma, a hormone-producing pancreatic tumour, covers it in full.
Gastrinoma
Ulcers that keep returning
Severe reflux, ulcers in unusual places or ones that return as soon as acid-lowering treatment stops, often with diarrhoea. Gastrinoma and Zollinger-Ellison syndrome explains the pattern and the tests.
Glucagonoma
A migrating rash with new diabetes
A characteristic spreading, crusting rash, a sore mouth, weight loss and blood sugar that has recently become difficult to control. The skin change is usually what finally prompts referral.
VIPoma
Large-volume watery diarrhoea
Persistent watery diarrhoea that continues even when you are not eating, with dehydration and a low potassium level on bloods. It is the volume, and the fact that fasting does not stop it, that stands out.
Rarer syndromes
Somatostatinoma and others
Uncommon patterns such as gallstones with diarrhoea, fatty stools and new diabetes together, or hormone effects usually associated with other glands. These are unusual and are settled by targeted testing.
Non-functioning
No hormone syndrome at all
The largest group by some way. Nothing hormonal to treat, which is why these tumours are usually found on imaging rather than through symptoms — and why the plan starts with grade, size and resectability.
If you have been handed a report using either label and no explanation of what it means for your treatment, bring it in. We will read it with you and say plainly what it changes. Book a free consultation or call 1800 202 8726.
12+ Centres in Hyderabad · Pick yours
CION cancer care is closer than you think.
We're never more than 30 minutes away. Same panel of specialists at every centre. Same tumour board reviews. Same NCCN protocols. Pick the closest one and call directly — or let us pick for you.
CION Ameerpet
CION Kukatpally
CION L.B. Nagar
CION Tolichowki
CION Masab Tank
CION Banjara Hills
CION Kompally
CION Balanagar
CION Siddipet
CION Sangareddy
Not sure which centre fits best? Tell us where you are — we'll suggest the closest one with the right specialists.
Help me pick the right centre
Beyond Hyderabad
35+ centres across Telangana & Andhra Pradesh
Travelling for treatment? We may have a centre right where you are.
Telangana
Andhra Pradesh
Don't see your city? Call 18002028726 — we'll find your nearest CION partner centre.
Meet the Specialists
17+ senior cancer specialists. One panel for your case.
Trained at AIIMS, Tata Memorial, and leading international centres. Combined 150+ years of experience. Every complex case is reviewed by 3+ of them — together.
Medical Oncologist
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
Medical Oncologist
Surgical Oncologist
Dr. Muralidhar Muddusetty
MBBS (AIIMS), MS (Surgery) (AIIMS), DNB (Surgical Oncology), MRCS (Edinburgh)
Surgical Oncologist
Surgical Oncologist
Surgical Oncologist
Dr. Vinay Mamidala
MBBS, MS(General Surgery), M.Ch(Surgical Oncology), FMAS, FARIS(Ongoing)
Surgical Oncologist
Radiation Oncologist
Radiation Oncologist
Radiation Oncologist
Hematologist
Interventional Radiologist
Dr. Mohammed Imran
Surgical Oncologist
Dr. Vajja Sandeep Kumar
MBBS, MS (General Surgery), DrNB (Surgical Oncology), FALS Oncology
Surgical Oncologist
Want a specific doctor for your case? Mention them when booking.
Book Free ConsultationBook an appointment with our specialist
Share your name and number — we'll call you back within 30 minutes to schedule your consultation.
The Label Guides the Plan. It Is Not the Whole Plan.
Grade, size and whether the tumour can be removed matter more. We will walk you through all of it.
What actually happens
How We Settle Which One You Have
-
The history, taken properly
Hormone syndromes are found by listening, not by scanning. When symptoms happen, what relieves them, what you were doing beforehand and how long the pattern has run decide which hormone is worth measuring.
In-house at CION -
Targeted hormone bloods, under the right conditions
These tests only mean something when they are taken correctly — fasting where required, and with any interfering medicines accounted for. A single badly timed sample is the commonest reason a functioning tumour is missed, or wrongly suspected.
Ordered and reported in-house at CION -
Locating the tumour on cross-sectional imaging
A pancreatic-protocol contrast CT, or an MRI, maps where the tumour sits, how large it is, its relationship to the vessels behind the pancreas and whether anything has spread to the liver.
Ordered and reported in-house at CION -
Functional imaging where the scan is not enough
Small functioning tumours can hide on a standard scan. Receptor-targeted imaging, including DOTATATE PET, is arranged when the biochemistry says a tumour is there and the CT cannot find it.
Coordinated with partner nuclear medicine centres; may be billed there -
Tissue, and the grade that comes with it
A sample is usually taken by endoscopic ultrasound with a fine needle. The grade read from that sample — how fast the cells are dividing — shapes the plan more than the hormone label does.
Endoscopy and biopsy coordinated with specialist partners; may be billed there -
One plan, agreed as a team
Imaging, biochemistry and pathology are reviewed together, so hormone control and tumour control are decided in the same conversation rather than separately. Pancreatic cancer treatment in Hyderabad sets out the options in full.
Tumour board at CION; systemic therapy in-house
Plainly stated
What CION Delivers, and What Is Coordinated
Saying this early saves an awkward conversation later. Your first consultation is free and lasts 45 minutes. It is a genuine review of your reports and your symptom pattern, not a booking appointment, and you are welcome to bring the scan disc and every blood result you have.
Delivered in-house at CION, across 35+ centres in Telangana and Andhra Pradesh: assessment of a suspected hormone syndrome and the ordering and reporting of the hormone and marker bloods that settle it; pancreatic-protocol CT, MRI/MRCP, CA 19-9 and routine bloods; medical oncology for neuroendocrine tumours, including somatostatin-analogue-class treatment, mTOR-inhibitor-class and TKI-class options, and chemotherapy where the grade calls for it; radiation, chemoradiation and SBRT; genetic counselling where an inherited syndrome such as multiple endocrine neoplasia type 1 is suspected; nutrition and pancreatic enzyme replacement; pain relief, psycho-oncology and supportive care; and long-term follow-up.
Coordinated with specialist HPB, gastroenterology, endoscopy and nuclear medicine partner centres, and may be billed there: all pancreatic surgery, from enucleation of a small functioning tumour to distal pancreatectomy or a Whipple procedure; endoscopic ultrasound and the biopsy taken through it; ERCP and biliary or duodenal stenting; staging laparoscopy; coeliac plexus block for pain; PET-CT and DOTATATE PET; and peptide receptor radionuclide therapy. We arrange these, we take part in the decisions, and we tell you in advance where each one happens and who will invoice you. We do not describe them as our own theatre, endoscopy or nuclear medicine lists, because they are not.
Take this to your appointment
Questions That Make the Label Useful
Written down, in the order they are most useful. None of them is a difficult question to ask.
- Is my tumour functioning or non-functioning, and how was that decided? Ask whether it was settled on symptoms, on a measured hormone level, or simply assumed because nothing obvious was reported.
- What is the grade? This is the answer that shapes the treatment sequence and the follow-up interval. It matters more than the hormone label does.
- If it is functioning, what is the plan for the hormone symptoms meanwhile? Hormone control should not wait for the tumour decision to be made.
- Can this tumour be removed, and who would do the operation? Ask which centre, which surgeon and who invoices you, so nothing about the billing is a surprise later.
- Do I need receptor-targeted imaging, and where is it done? Useful when a small functioning tumour is suspected but has not yet been seen on the CT.
- Should anyone in my family be assessed? A small number of these tumours sit within an inherited syndrome, and that is worth settling once rather than wondering about it for years.
If you are still working out where a neuroendocrine tumour sits in the wider picture, start with the complete pancreatic cancer guide, then bring your reports to us. Book a free consultation or call 1800 202 8726.
Take the next step
Understand Your Tumour Before Deciding Anything
A clear explanation of what your report says makes every decision that follows easier. We walk this journey with you.
Real Stories. Real Voices.
15,000+ patients chose CION. Hear from them directly.
These aren't paid endorsements or written reviews. These are video testimonials from real patients and families — recorded on their own phones, in their own words. Pick any one. Watch it. Then decide.
4.8★800+ Google reviews
50+video testimonials
15,000+patients treated
Read all 800+ reviews on Google
Start Your Story. Book Free Consultation.
Common questions
Functioning and non-functioning PNETs — your questions answered
What does 'functioning' mean in a pancreatic neuroendocrine tumour?
It means the tumour is releasing an active hormone in enough quantity to cause a recognisable set of symptoms. Pancreatic neuroendocrine tumours grow from the hormone-producing islet cells of the pancreas, so some of them keep making a hormone and release it without the normal controls. The symptoms then come from the hormone rather than from the size of the tumour, which is why people are often investigated for a metabolic, gastric or skin problem long before the pancreas is suspected. A non-functioning tumour either makes no active hormone at all, or makes so little that nothing shows up in your bloods or in how you feel. Both are the same family of tumour; the label simply records whether a hormone syndrome is present.
Is a non-functioning PNET less serious than a functioning one?
No, and assuming so is the commonest misunderstanding we correct in clinic. The label describes symptoms, not behaviour. What actually predicts how a neuroendocrine tumour will behave is its grade, how far it has spread and whether it can be removed completely. Non-functioning tumours are frequently larger when they are found, precisely because nothing prompted a scan earlier, so they can be the more advanced of the two at diagnosis. Equally, a functioning tumour can cause symptoms that are dangerous in themselves and need controlling quickly, even when the tumour is tiny. Neither label is good news or bad news on its own. Ask instead for the grade and the stage, because those are what shape the plan.
Which hormone syndromes are recognised?
The ones seen most often are insulinoma, where the tumour releases insulin and causes repeated low blood sugar episodes, and gastrinoma, which drives acid production and causes stubborn or recurrent ulcers, reflux and diarrhoea. Less common are glucagonoma, which produces a characteristic spreading rash together with weight loss and blood sugar that has become difficult to control, and VIPoma, which causes large-volume watery diarrhoea that continues even when you are not eating, along with dehydration and a low potassium level. Rarer patterns such as somatostatinoma exist as well. Having any of these symptom patterns does not mean you have a pancreatic tumour, because every one of them has far more common explanations. It means the pattern deserves a proper explanation rather than being treated piece by piece.
How is it decided which type I have?
It starts with the history rather than a scan. When your symptoms occur, what relieves them, and how long the pattern has run all point to which hormone is worth measuring. Targeted hormone bloods are then taken under carefully controlled conditions, because timing, fasting and any interfering medicines can change the result completely. A pancreatic-protocol contrast CT or an MRI locates the tumour and shows its relationship to the vessels behind the pancreas. Where the biochemistry indicates a functioning tumour that the scan cannot find, receptor-targeted imaging such as DOTATATE PET is arranged with our partner nuclear medicine centres and may be billed there. A tissue sample, usually taken by endoscopic ultrasound with a fine needle, then gives the grade.
Does the functioning label change my treatment?
It adds to the plan rather than replacing it. For a functioning tumour there are two jobs running in parallel: controlling the hormone effects so that you are safe and comfortable, and dealing with the tumour itself. Hormone control often begins straight away, before any decision about surgery has been made, and for some syndromes it is the more urgent of the two. The tumour side of the plan, however, is chosen on grade, size, spread and whether the tumour can be removed, exactly as it would be for a non-functioning tumour. Removing a functioning tumour completely usually settles the hormone symptoms as well, which is why surgery is considered seriously in this group even for small tumours.
Can a non-functioning PNET start producing a hormone later?
It is uncommon, but the label is not permanently fixed and should be revisited if your symptoms change. A tumour reported as non-functioning was described that way on the assessment made at the time. If a clear new pattern appears afterwards, particularly repeated low blood sugar episodes, unexplained large-volume diarrhoea or ulcers that keep returning, it is worth raising rather than putting down to something unrelated. Occasionally a hormone syndrome was present from the start but too subtle to be picked up, and only becomes obvious once someone connects the symptoms together. Either way, the response is the same: describe the pattern to your oncologist and ask whether the relevant hormone bloods should now be checked.
What does CION do for PNETs, and what happens at the first visit?
The first consultation is free and lasts 45 minutes. We go through your reports with you, say plainly whether the functioning question has actually been settled or only assumed, and set out what still needs testing. Delivered in-house across our 35+ centres: hormone-syndrome assessment and the bloods that settle it, pancreatic-protocol CT and MRI, CA 19-9 and routine bloods, systemic therapy for neuroendocrine tumours including somatostatin-analogue-class treatment, radiation where it is appropriate, genetic counselling, nutrition and pancreatic enzyme support, pain relief and long-term follow-up. All pancreatic surgery, endoscopic ultrasound and biopsy, ERCP and stenting, coeliac plexus block, PET-CT and DOTATATE PET and peptide receptor radionuclide therapy are coordinated with specialist partner centres and may be billed there. Bring your scan disc and every blood result you have.
Medical disclaimer: This page explains the difference between functioning and non-functioning pancreatic neuroendocrine tumours and is reviewed by a CION medical oncologist with reference to the WHO classification of neuroendocrine neoplasms and NCCN guidance on neuroendocrine tumours. It is general information and not a diagnosis; whether a hormone syndrome is present, and what should be done about it, must be settled with a doctor who has seen your bloods and your scans. Hormone-syndrome assessment, hormone and marker bloods, pancreatic-protocol CT, MRI/MRCP and CA 19-9, medical oncology including systemic therapy for neuroendocrine tumours, radiation, chemoradiation and SBRT, genetic counselling, nutrition and pancreatic enzyme support, pain relief, psycho-oncology and survivorship care are delivered by CION. All pancreatic surgery, endoscopic ultrasound and biopsy, ERCP and biliary or duodenal stenting, staging laparoscopy, coeliac plexus block, PET-CT and DOTATATE PET, and peptide receptor radionuclide therapy are coordinated with specialist hepatobiliary, gastroenterology, endoscopy and nuclear medicine partner centres and may be billed there.