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Pancreatic neuroendocrine tumor (islet cell tumor)

Also called: PNET, Insulinoma, Gastrinoma

A tumor of the pancreas's hormone cells. It usually grows more slowly than typical pancreatic cancer.

Typical ageOver 50
OutlookOften better than typical pancreatic cancer

Overview

Functioning tumors cause symptoms from extra hormones; non-functioning tumors are often found by chance on a scan.

Surgery is the main treatment. Other options include hormone-blocking shots (somatostatin analogs), targeted drugs, and radioactive treatment (PRRT).

Symptoms

Common signs:

  • Low blood sugar spells: shakiness, sweating, confusion (insulinoma)
  • Stomach ulcers that keep coming back with diarrhea (gastrinoma)

Less common

  • Belly pain
  • Watery diarrhea
  • Rash, weight loss, or high blood sugar

Look up a symptom: Burning or gnawing stomach pain · Diarrhea · Losing weight without trying · Low blood sugar · Stomach pain

When to get medical care

Call 911Trouble breathing, heavy bleeding, a seizure, sudden confusion, or fainting: call 911.
Get care todayFever during cancer treatment, or new or quickly worsening symptoms.
See a doctor soonSymptoms lasting more than 2 to 3 weeks.

Causes

Changes in a cell's genes that make it grow out of control. Most happen by chance; some are linked to the risk factors below or to inherited genes.

Does it spread or run in families?

  • Cancer isn't contagious. You can't catch it from someone.

Who is more likely to get it

  • MEN1 syndrome
  • von Hippel-Lindau syndrome

Diagnosis

Tests look for the cause. Many people checked for these symptoms turn out not to have cancer.

Questions you may be asked

  • When symptoms started and whether they're getting worse
  • Family history of cancer
  • Past illnesses, treatments, and exposures

The exam

A physical exam, focused on where the symptoms are.

Tests

Tests, if needed:

  • Hormone blood tests:
  • CT, MRI, or DOTATATE PET scan:
  • Endoscopic ultrasound with biopsy:

Treatment

Treatment depends on the type, stage, and your overall health. A cancer care team makes a plan with you.

Self-care

  • Write down symptoms and when they started
  • Bring someone with you to appointments
  • Ask for copies of test results
  • Ask about clinical trials: they can offer new treatments
  • Quit smoking: it helps at every stage

Surgery, somatostatin analog shots, targeted drugs, PRRT, or chemotherapy.

Prevention

To lower risk or find it early:

  • No known way to prevent it

Which doctor treats this

  • Start with your primary care provider (family doctor or internist).
  • They may send you to an oncologist (cancer doctor), often working with surgeons and radiation doctors.

Living with it

  • Keep a simple notebook of symptoms, medicines, and questions for visits.
  • Ask for a survivorship care plan when treatment ends.
  • Gentle activity, like walking, can ease tiredness.
  • A cancer diagnosis can affect mood. Tell the care team if you or your family feel down or anxious.

Support groups and helplines

Back to school, work, or sports

  • Many people keep working during or after treatment.
  • Ask about changes that help, like flexible hours. Workers may be covered by the ADA.

Pregnancy and breastfeeding

  • If you're pregnant or planning to be, tell your cancer team. Some treatments can harm a baby.
  • Ask about saving eggs or sperm before treatment if you may want children later.

For caregivers

  • Go to visits when you can and take notes.
  • Keep a list of medicines, allergies, and doctors in one place.
  • Learn the warning signs that need fast care, like fever during treatment.
  • Take breaks and ask for help. Caregivers need care too.

Outlook

Outlook depends on the type and stage. Cancers found early are usually easier to treat, and treatments keep improving.

Support is available: ask about social workers, nutrition help, and support groups.

Getting ready for your visit

Bring a list of symptoms and medicines.

What to bring

  • A list of medicines and supplements
  • Notes on when symptoms started
  • Past test results and scans

Questions to ask

  • Is the tumor making hormones?
  • Is DOTATATE PET scanning right for me?
  • What stage is it, and what are the treatment options?
  • Are there clinical trials for me?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Pancreatic neuroendocrine tumor (islet cell tumor)

Sources

Last updated 2026-11-13.