Neuroendocrine Tumors


Cancers called neuroendocrine tumors (NET) develop in specialized cells known as neuroendocrine cells. These cells exhibit both the characteristics of nerve cells and those of endocrine cells that produce hormones. They link your nervous system with your endocrine system, which controls your hormones.

Neuroendocrine tumors come in different types, some are slow-growing and some are fast-growing. The tumors that excessively produces hormones are called functional neuroendocrine tumors. While a non-functional neuroendocrine tumor may not produce enough amount, or may not produce hormones that may cause symptoms.

The tumors tend to develop anywhere throughout the body. The lungs, appendix, small intestine, rectum, and pancreas are where neuroendocrine tumors most frequently develop.

Neuroendocrine tumors are a rare type of cancer, but due to the efficiency of modern diagnostics they are identified very quickly and therefore the number of patients who live for years with NET has risen. The type of tumor, its location, the aggressiveness, and the severity affect the diagnosis and treatment of the disease.

Types of neuroendocrine tumors

    • Adrenal cancer: Can develop at any age and is also known as adrenocortical carcinoma. One or both of the adrenal glands that are situated on top of your kidneys might develop adrenal carcinoma, a rare kind of cancer. Hormones in the adrenal glands are responsible to give instructions to the organs and tissues all over the body.
    • Carcinoid tumors: Is a slow-growing cancer that can develop in many locations throughout the body. The digestive tract (stomach, appendix, small intestine, colon, or rectum) or the lungs are where carcinoid tumors, a subset of neuroendocrine tumors, typically develop.
    • Merkel cell carcinoma: This is rare kind of skin cancer frequently affecting the face, head, and neck. It typically manifests as a flesh-colored or bluish-red nodule. Neuroendocrine carcinoma of the skin is another name for Merkel cell cancer.
    • Pancreatic neuroendocrine tumor: Pancreatic neuroendocrine tumors (pNET) or islet cell tumor are a rare type of cancer that develop in the hormone producing cells of the pancreas.
    • Paraganglioma: An abnormal cell growth known that arises from a particular kind of nerve cells (chromaffin cells) that is present throughout the body.
    • Phenochromocytoma: An adrenal gland tumor known as a pheochromocytoma is uncommon and is typically noncancerous (benign). The upper part of the kidneys on both sides is where the adrenal glands are located. As a component of the body’s endocrine system, the adrenal glands produce hormones. The hormones released from the tumor can cause high blood pressure, sweating, headache and panic attack symptoms.


Neuroendocrine tumors may initially not show any symptoms. Your symptoms may vary depending on the tumor’s location and whether it secretes extra hormones.

Signs and symptoms of neuroendocrine tumors may include:

  • Pain caused by a developing tumor
  • Developing lump under the skin
  • Fatigue or tiredness
  • Unexplained weight loss.

Neuroendocrince tumor with are functional tumors that overproduce hormones, may result in:

  • Diarrhea
  • Abdominal cramps
  • Skin flushes or skin rashes
  • Dizziness
  • Frequent urination
  • Excessive thirst

If the patient is experiencing any persistent signs or symptoms that is concerning, schedule a visit with a specialist.


Neuroendocrine tumors have an unknown specific cause. These cancers start in neuroendocrine cells, which are similar to nerve cells and hormone-producing cells. Neuroendocrine cells can be found all over your body.

Neuroendocrine tumors form when neuroendocrine cells’ DNA changes (mutates). Some neuroendocrine tumors grow at a slow pace while others are aggressive, invading and destroying healthy body tissue and spreading to other parts of the body (metastasize).

Risk factors

People who inherit genetic syndromes that raise the risk of cancer are more likely to develop neuroendocrine tumors. Some instances are:

    • Multiple endocrine neoplasia, type 1 (MEN 1): the thyroid, parathyroid, or adrenal glands become hyperactive or develop tumors as a result of this condition.
    • Multiple endocrine neoplasia, type 2 (MEN 2): pituitary, parathyroid, and pancreas may become hyperactive or develop tumors as a result of this illness.
    • Von Hippel-Lindau disease: rare benign tumors develop at different parts throughout the body.
    • Tuberous sclerosis: early childhood skin birthmarks, epilepsy, autism, and developmental delays are some of this condition’s symptoms.
    • Neurofibromatosis: a rare condition that where tumors develop on the skin and nerves, and cause harm to the eyes and other parts of the body.