Is every pNET operated on?

No. In selected small, low-grade, non-functional cases, monitoring can be considered; the decision depends on the tumor's specific characteristics.

What does functional pNET mean?

It's a type of pNET that secretes excess hormones, causing specific symptom clusters such as recurrent hypoglycemia.

How is pNET found incidentally?

Since non-functional pNETs mostly don't cause hormonal symptoms, they are often found by chance on imaging done for another reason.

How is a pNET diagnosis confirmed?

After imaging findings, the diagnosis is usually confirmed through tissue sampling and pathological examination.

What kind of surgery is done for pNET?

It depends on the tumor's location in the pancreas; the Whipple procedure may be considered for tumors in the head, and distal pancreatectomy for tumors in the body or tail.

Is pNET always malignant?

No, its behavior depends on the tumor's grade and other features, which is why not every pNET is evaluated in the same way.

What Is a Pancreatic Neuroendocrine Tumor (pNET)?

Last updated: 14 September 2026Medical content lead: Op.Dr.Gökhan ATEŞ

Quick Answer

pNET is a group of tumors arising from the hormone-producing (endocrine) cells of the pancreas and differs from the more common pancreatic cancer. Functional pNETs secrete excess hormones and cause specific symptom clusters, while non-functional pNETs are mostly found incidentally. The treatment decision depends on the tumor's grade, stage, size, location, and whether it has spread; the choice between monitoring, surgery, and systemic treatment is made individually by a multidisciplinary team. Not every pNET needs to be operated on.

Patients diagnosed with a pancreatic neuroendocrine tumor (pNET) often confuse it with the more familiar concept of 'pancreatic cancer.' In fact, pNETs arise not from the pancreas's digestive-enzyme-producing cells but from its hormone-producing cells, and generally show different biological behavior than the more common exocrine pancreatic adenocarcinoma. Understanding this distinction can make the diagnosis and treatment process feel less alarming.

How does pNET differ from exocrine pancreatic cancer?

Most of the pancreas is made up of exocrine tissue, which produces digestive enzymes; the most common type of pancreatic cancer also arises from this tissue. pNETs, on the other hand, arise from hormone-producing endocrine cells found in clusters within the pancreas. This different origin means pNETs generally can have a different course and growth rate, but that doesn't mean every pNET will behave slowly or be harmless.

Functional and non-functional pNET

Functional pNET: secretes excess hormones and can cause specific syndromes such as insulinoma or gastrinoma; symptoms linked to these syndromes (such as recurrent hypoglycemia, severe diarrhea, or widespread flushing) can prompt patients to seek medical evaluation
Non-functional pNET: doesn't cause a hormonal syndrome, so it's often found incidentally on imaging done for another reason
In both groups, the diagnostic evaluation includes imaging, hormone levels (when needed), and pathological examination

What is assessed during diagnosis?

Imaging methods (CT, MRI, and specialized nuclear medicine imaging when needed) are used to assess the tumor's location, size, and whether it has spread. When there is suspicion, tissue sampling is used to confirm the pathological diagnosis. The pathology report determines the tumor's grade, which indicates how quickly the tumor cells are proliferating and plays an important role in treatment planning.

Symptoms related to a hormonal syndrome

In functional pNETs, different symptom clusters can appear depending on the type of hormone secreted. For example, excess insulin secretion can cause recurrent hypoglycemic episodes (sweating, palpitations, confusion), while excess of certain other hormones can cause severe diarrhea or widespread flushing. When such symptoms are noticed, medical evaluation is needed to investigate the underlying cause.

How is the treatment decision shaped?

The tumor's grade, stage, size, and location
Whether it has spread (to regional lymph nodes or distant organs)
Whether it is functional and how severe any hormone-related symptoms are
The patient's overall health and surgical risk
The decision is made through a multidisciplinary evaluation involving surgery, medical oncology, radiology, and nuclear medicine specialists

Balancing monitoring, surgery, and systemic treatment

For some small, low-grade, non-functional pNETs, close monitoring can be considered in selected cases. Surgical resection is an option considered in appropriate cases; depending on the tumor's location in the pancreas (head, body, or tail), different surgical techniques (such as the Whipple procedure or distal pancreatectomy) may come into play. For cases that have spread or aren't suitable for surgery, systemic treatment options are used instead.

None of these decisions follow a single rule — not every pNET is treated the same way, and there is no general rule that 'every pNET must be operated on.'

If a functional pNET is suspected, these findings need urgent evaluation

Repeated episodes of severe hypoglycemia with confusion, sweating, or palpitations
Severe, watery diarrhea with signs of rapid fluid loss
A flushing episode together with shortness of breath or low blood pressure
New-onset jaundice or severe abdominal pain
Unexplained rapid weight loss

Kaynaklar / Sources

Frequently Asked Questions

No. pNET arises from the hormone-producing cells of the pancreas and is a different tumor group from the more common exocrine pancreatic cancer.

Distal Pancreatectomy

Patient information on distal pancreatectomy: scope of the operation, when the spleen is preserved or removed, risks, and enzyme and glucose monitoring afterwards.

Whipple Procedure

Patient information on the Whipple procedure: which organs are removed, how the digestive tract is reconstructed, risks, preparation and recovery.

What Is Distal Pancreatectomy, and When Is the Spleen Preserved?

Distal pancreatectomy is considered for selected lesions in the body or tail of the pancreas; whether the spleen is preserved depends on the nature of the lesion.

What Is the Whipple Procedure, and Who Is It For?

The Whipple procedure is a major operation considered for selected conditions affecting the head of the pancreas and the surrounding periampullary region; it is not suitable for every patient.

A Pancreatic Cyst Was Found — What Happens Next?

A pancreatic cyst found incidentally on imaging is usually not an emergency, but its type still needs to be identified and followed at the right interval.

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The information on this page is provided for general patient education only and does not replace diagnosis, treatment or any surgical decision. An assessment appropriate for you can only be made after a clinical examination and the necessary investigations.