What Are The First Symptoms Of Neuroendocrine Tumors & How Do You Test For It?

Earlier neuroendocrine tumors were known as carcinoid tumors. Neuroendocrine tumors have neurogenic properties as well as endocrinal properties. These tumors can arise anywhere in the body. But the most common sites are the gastrointestinal system and the respiratory tract.

Out of all the cases diagnosed with neuroendocrine tumors, about 62%-67% of them are found to be gastrointestinal in origin and about 22%-27% are found to be originating in the lungs.

The exact cause of neuroendocrine tumors is yet to be discovered. There are certain risk factors that can lead to this disease like a family history of certain diseases like multiple endocrine neoplasia type 1. This disease is comparatively more common in African-Americans than the white population. (1)

What Are The First Symptoms Of Neuroendocrine Tumors?

What Are The First Symptoms Of Neuroendocrine Tumors?

The symptoms experienced by different people with neuroendocrine tumors are not the same. The symptoms vary from person to person due to many reasons like the location of the tumor, if the tumor is capable of secreting hormone or not, etc.

Mostly neuroendocrine tumor does not show any symptoms, it just gets diagnosed accidentally in an X-ray or while getting operated for some other disease.

Symptoms of neuroendocrine tumors are:

General symptoms:

Symptoms due to secretion of hormones by the tumor:


Hyperglycemia- it means an increase in the blood sugar levels. Due to hyperglycemia, the patient has symptoms like an increase in the frequency of urination, an increase in appetite and increased thirst.

Facial flushing

Hypoglycemia- means a decrease in the blood sugar levels. Due to hypoglycemia, the patient has symptoms like sweating, fatigue, dizziness, drowsiness, fainting, and fainting.

  • Skin rash
  • Gastric ulcers
  • Anxiety
  • Confusion
  • Various nutritional deficiencies

Symptoms based on the location and size of the tumor mass:

  • Continuous pain in the area where the tumor is growing
  • Presence of a lump in a certain part of the body
  • Jaundice
  • Alteration in the bladder and bowel habits
  • Cough
  • Hoarseness of voice
  • Unexplained bleeding (2)

How Do You Test For Neuroendocrine Tumors?

Following are the investigations done by the doctor to diagnose neuroendocrine tumors:

Blood And Urine Tests: Different hormonal studies are done to find out abnormal hormones in the blood. A urine test for the levels of 5-HIAA, which is a byproduct of the serotonin breakdown process is also done. The level of serotonin in the blood is also checked.

Biopsy: Biopsy is an invasive procedure in which a small tissue from the tumor mass is excised and examined microscopically. This helps in the diagnosis of neuroendocrine tumors.

Endoscopy: Endoscopy is a procedure in which the doctor looks for the abnormalities in the gastrointestinal system of the patient by inserting a scope with a camera inside the body of the patient. Upper endoscopy is performed for the examination of the stomach and esophagus while colonoscopy is performed for examining the rectum and colon.

The choice of treatment for neuroendocrine tumors depends on certain factors like stage and grade of the tumor, type of neuroendocrine tumor, side effects of the treatment and overall health of the patient.

Surgical Interventions: The tumor mass can be removed surgically along with some of the surrounding healthy tissue. When complete excision of the tumor mass is not possible, the doctor may perform debulking surgery where most of the tumor mass as much as possible is excised.

Chemotherapy: Under this method, various drugs are used to kill the cancer cells and to stop their growth and multiplication.

There are many side effects of chemotherapy like nausea, vomiting, fatigue, hair loss, decreased appetite, increased chances of infection and diarrhea.

Targeted Therapy: This therapy focuses only on the cancer cells and destroys their proteins and genes in order to stop the growth of the tumor. This treatment has a benefit that the extent of damage to the healthy cells is reduced.

The commonly used drug for this therapy is everolimus and the other is sunitinib.

Immunotherapy: This therapy focuses on boosting up the immune system of the patient. Interferon alfa-2b is a type of immunotherapy.

Radiotherapy: Under this therapy, a strong beam of X-rays is projected on the body part where tumor mass is present so that the tumor cells get destroyed. (4)


There are no specific symptoms related to neuroendocrine tumors because the symptoms vary according to the type of tumor. Many times, the patient does not show any symptoms is the tumor mass is not capable of secreting hormones. Most of the times these tumors are diagnosed accidentally while performing an X-ray or while getting operated for some other disease. The symptoms of neuroendocrine tumors are – loss of appetite, weight loss, etc. There are many diagnostic methods used to diagnose neuroendocrine tumors like X-ray, ultrasonography, blood and urine tests, CT scan, MRI, biopsy, etc.


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