Neuroendocrine Tumors – Symptoms and Causes
What Are Neuroendocrine Tumors?
Neuroendocrine tumors start in special cells that share qualities with both nerve cells and hormone-producing cells. These rare cancers can develop anywhere in the body, though they most commonly appear in the:
- Lungs
- Appendix
- Small intestine
- Rectum
- Pancreas
These tumors vary in how they behave. Some grow slowly while others spread quickly. They are classified as functional (producing excess hormones) or nonfunctional (producing few or no hormones). The symptoms a person experiences often depend on this classification.
Several factors determine how doctors approach these tumors:
- The specific tumor type
- Where it’s located
- Whether it makes extra hormones
- How aggressive it appears
- If it has spread to other areas
Early detection and proper classification help healthcare providers develop the most effective treatment plan for each patient.
Types of Neuroendocrine Tumors
Neuroendocrine tumors can appear in different parts of the body. These types include:
- Adrenal cancer – affects the adrenal glands above the kidneys.
- Carcinoid tumors – commonly found in the digestive tract and lungs.
- Merkel cell carcinoma – a rare skin cancer.
- Pancreatic neuroendocrine tumors – develop in the hormone-producing cells of the pancreas.
- Paraganglioma – forms near certain blood vessels and nerves outside the adrenal glands.
- Pheochromocytoma – develops in the inner part of the adrenal glands.
Each type of tumor can produce different hormones and cause varying symptoms.
Common Signs
Neuroendocrine tumors often show no early signs. When symptoms appear, they vary based on the tumor’s location and hormone production.
General symptoms may include:
- Pain where the tumor grows
- A lump you can feel under your skin
- Unusual tiredness
- Unexplained weight loss
If the tumor produces extra hormones (functional tumors), you might experience:
- Skin flushing
- Diarrhea
- Frequent need to urinate
- Feeling very thirsty
- Dizziness
- Shakiness
- Skin rashes
Medical Help
Contact your doctor if you notice any ongoing symptoms that concern you. It’s important to get unusual symptoms checked, even if they seem minor at first.
Reasons for Neuroendocrine Tumor Development
Scientists don’t fully understand why neuroendocrine tumors form. These tumors start in neuroendocrine cells, which share features with both nerve cells and hormone-producing cells found throughout the body.
The main cause appears to be DNA changes or mutations in these cells. When DNA, which controls cell function, develops mutations, it can instruct neuroendocrine cells to multiply too quickly and form tumors.
Growth patterns vary significantly among these tumors:
- Slow-Growing Tumors: Some develop very gradually over years.
- Aggressive Tumors: Others grow rapidly, invading nearby tissues.
- Metastatic Tumors: Some spread to distant body parts.
The behavior of these tumors depends on several factors, including the location of the original tumor and the specific type of neuroendocrine cells involved.
Risk Factors
People with certain genetic conditions have a higher chance of developing neuroendocrine tumors. These inherited syndromes include:
- Multiple Endocrine Neoplasia Type 1 (MEN 1)
- Multiple Endocrine Neoplasia Type 2 (MEN 2)
- Von Hippel-Lindau Disease
- Tuberous Sclerosis
- Neurofibromatosis
These genetic conditions can cause tumors to form in hormone-producing glands and other parts of the body. People with family members who have these syndromes may want to consider genetic testing to assess their risk.
