Neuroendocrine Tumors Explained: Symptoms, Causes & Treatment Options

When you hear the word tumor, your mind might immediately jump to cancer, chemotherapy, or scary medical jargon. But neuroendocrine tumors (NETs) are a little different and often misunderstood. They don’t always act like the cancers we usually think of, and sometimes people live with them for years before even knowing they have one.

So, what exactly are neuroendocrine tumors? How do they show up, and why do they often get misdiagnosed? If you’ve ever felt lost in medical terms or simply want a clear, plain-English breakdown, you’re in the right place.

Let’s break down everything you need to know about NETs.

What Are Neuroendocrine Tumors and Where Do They Form?

At their core, neuroendocrine tumors are cancers that begin in special cells called neuroendocrine cells. These cells are unique because they have two jobs: they act like nerve cells, and they also make hormones that help regulate important functions like growth, digestion, and metabolism.

That means NETs can technically develop almost anywhere in the body. But the most common spots are:

• The lungs

• The small intestine

• The pancreas

  
  

Since these cells are scattered in different organs, NETs don’t look or behave the same in everyone, which makes them tricky to pin down.

Types of Neuroendocrine Tumors

Doctors classify NETs in two main ways:

Based on hormone activity:

• Functional NETs produce hormones that can cause noticeable symptoms, such as flushing, diarrhea, or changes in blood sugar levels.

• Non-functional NETs don’t release hormones but can still cause problems when they grow large or press on nearby organs.

Based on location:

• Gastrointestinal NETs (GI-NETs): The most common type, usually found in the intestines, rectum, or appendix. They were once called “carcinoid tumors.”

• Lung NETs: The second most common, starting in the lungs or airways. These were also once called “carcinoid tumors.”

• Pancreatic NETs (P-NETs): A less common type that begins in the pancreas and behaves differently from other pancreatic cancers. People with P-NETs may need treatments similar to those used in pancreatic cancer treatment Singapore, such as surgery, medicines, or targeted therapy.

Much more rarely, NETs can also form in the thyroid, parathyroid, pituitary gland, adrenal glands, or thymus.

Are Neuroendocrine Tumors Always Cancerous?

The short answer is yes, NETs are almost always considered cancer. But that does not mean they all behave the same way.

Some NETs grow so slowly that people may never have symptoms, while others can spread and cause serious health issues. On a global scale, NETs affect about 6 in every 100,000 people.

They are rare, and most people diagnosed are between the ages of 50 and 60. Thanks to better scans and diagnostic tests, doctors are spotting them earlier than before.

Symptoms of Neuroendocrine Tumors

This is where things get confusing. NETs often stay silent until they grow or start affecting nearby organs. When symptoms do appear, they can vary in appearance depending on the type and location of the tumor.

• Common signs include:

• Stomach pain or discomfort

• Flushing or redness of the skin

• Diarrhea or constipation

• Nausea and vomiting

• Unexpected weight loss and tiredness

• Hormone-related issues like low or high blood sugar, palpitations, dizziness, or sweating

• Cough or shortness of breath for lung NETs

• A noticeable lump or mass in some cases

Of course, these symptoms can overlap with dozens of everyday conditions, which is why NETs often go undetected for a long time.

What Causes Neuroendocrine Tumors?

The exact cause is still a mystery. NETs happen when neuroendocrine cells start dividing uncontrollably and form tumors.

That said, certain genetic conditions can raise the risk, including:

• Multiple endocrine neoplasia (MEN1): A condition that triggers tumors in multiple glands.

• Von Hippel-Lindau syndrome: Linked to both cancerous and non-cancerous growths.

• Neurofibromatosis type 1: Causes nerve and skin tumors.

• Tuberous sclerosis complex: Leads to benign tumors, often in the brain.

• Cowden syndrome: Causes tumor-like growths and increases cancer risk.

Most people who develop NETs, however, do not have a family history or genetic syndrome.

Possible Complications from NETs

Because some NETs produce excess hormones, they can trigger a condition called carcinoid syndrome. This leads to flushing, diarrhea, wheezing, and in severe cases, a rare but dangerous event known as carcinoid crisis, which can be life-threatening.

Other complications depend on where the tumor grows:

• Digestive blockages and pain, if located in the intestines

• Jaundice if the pancreas or liver is involved

• High blood pressure if tumors affect the adrenal glands

• General fatigue and weight changes

Managing these complications is just as important as treating the tumor itself.

How Are Neuroendocrine Tumors Diagnosed?

Diagnosis is often delayed because early symptoms mimic more common conditions. Some patients only discover their NETs during routine scans for something unrelated. For example, someone might go in for a gallbladder issue or a colonoscopy in Singapore and discover a tumor by accident.

Others notice hormone-related symptoms that push doctors to investigate further. Common tools for diagnosis include imaging scans, biopsies, and blood tests that check for hormone levels.

Treatment Options for NETs

Surgery is usually the first choice, especially if the tumor has not spread too far. Advances in laparoscopic and robotic surgery allow doctors to remove tumors with smaller cuts, faster recovery, and less pain.

When surgery alone is not enough, other options may include:

• Chemotherapy to slow tumor growth

• Radiation therapy, including advanced techniques like proton therapy

• Targeted therapy or immunotherapy, depending on the tumor type

• Symptom management for hormone-related problems

  
  

Treatment is usually handled by a team of specialists, including surgeons, oncologists, and radiologists, ensuring that care is personalized. If you are looking for a trusted cancer clinic Singapore offers several centers with multidisciplinary teams that can guide you through every stage of treatment.

Can Neuroendocrine Tumors Be Cured?

If caught early and completely removed, NETs can be cured. The challenge is that many are discovered late, after they have already spread.

In those cases, treatment focuses on slowing growth, controlling symptoms, and improving quality of life. Many people live for years managing NETs as a chronic condition.

Final Thoughts

Neuroendocrine tumors may be rare, but awareness is growing, and so are the options for diagnosis and treatment. While they can be tricky to spot, understanding the symptoms, risks, and available care can make all the difference.

The most important thing to remember is this: not every tumor behaves the same way, and with the right medical guidance, many people live long, fulfilling lives while managing NETs.

If you are concerned about symptoms or simply want expert advice, don’t hesitate to reach out to a cancer doctor Singapore residents trust. Your health is worth prioritizing, so book your consultation today and take the first step toward peace of mind.