Neuroendocrine tumors


There are many types of neuroendocrine tumors that affect many areas of the body. They are most frequently found in the gastrointestinal tract, pancreas, liver and lungs. They are treatable, especially when cared for by a team of expert physicians.

Carcinoids, Carcinomas, Pancreatic and Other Neuroendocrine Tumors

Neuroendocrine tumors start in cells that communicate with the nervous system and release hormones. The cells perform functions such as regulating air and blood flow in the lungs and the speed that food moves through the gastrointestinal (GI) tract. While not all neuroendocrine tumors are malignant (cancerous), a doctor may recommend removing benign (non-cancerous) tumors as well if they cause problems by boosting hormone production.

Neuroendocrine tumors are found throughout the body, including the lungs and the GI tract. Tumor types include:

  • Carcinoids - The most common neuroendocrine tumors, carcinoids typically grow slowly and usually appear in the small intestine, rectum and other parts of the GI system. Carcinoids can make high levels of hormone-like substances called neuropeptides and amines and may not cause any symptoms.
  • Pheochromocytoma - This rare tumor develops in the adrenal gland and can boost adrenaline even if benign, causing problems.
  • Merkel Cell Cancer - This rare, aggressive cancer forms beneath the skin and in the hair follicles of the head and neck.
  • Pancreatic Neuroendocrine (Islet Cell) Tumors - This family of pancreatic tumors can cause a spike in hormones like insulin. The tumors are different than other types of pancreatic cancer. 
  • Neuroendocrine Carcinomas - Approximately 60 percent of neuroendocrine tumors don’t fit a specific cancer type and are included in this broader category.

Our approach

A Team Approach to Neuroendocrine Tumors

Successful neuroendocrine tumor care requires a team of experienced doctors with different specialties working together. The multidisciplinary team at Northwell Health understands that each patient is unique and they stay in constant contact with each other during diagnosis and treatment. They also meet once a week to share ideas and review each step of care.


Sometimes neuroendocrine tumors do not cause noticeable problems. But a patient may also experience one or more of these symptoms, depending on what type of neuroendocrine tumor they have:

  • GI Carcinoids

    • Flushed face
    • Diarrhea
    • Abdominal pain
    • Asthma
    • Rash
    • Heart disease
    • Intestinal bleeding
    • Pellagra (scale-like sores, diarrhea and mental disturbances)
    • Melena (dark, tar-like stools)
  • Lung Carcinoids

    • Cough
    • Wheezing
    • Pneumonia
  • Pheochromocytoma

    • High blood pressure (hypertension)
    • Anxiety attacks
    • Fever
    • Headaches
    • Sweating
    • Nausea
    • Vomiting
    • Clammy skin
    • Rapid pulse
    • Heart palpitations
  • Merkel Cell Cancer

    • Skin lumps that are painless, firm and shiny
  • Pancreatic Neuroendocrine Tumors

    • Ulcers
    • Diarrhea
    • Confusion
    • High blood sugar (hyperglycemia), which increases urination, thirst and hunger
    • Low blood sugar (hypoglycemia), which causes fatigue, nervousness, shakiness, dizziness, light-headedness, sweating, seizures and fainting
    • Rash on the face, abdomen or lower extremities
    • Too little potassium in the blood, possibly causing an irregular heartbeat, muscle cramping and weakness, and decreased reflexes)
    • Too little stomach acid, possibly causing cause digestive problems and poor vitamin and nutrient absorption
    • Flushed face, neck or chest
    • Fatigue
    • Nausea
    • Type 2 (adult onset) diabetes
    • Gallstones
    • Steatorrhea, a condition that causes oily, loose, foul-smelling stools because the body can’t absorb fat
    • Weight loss or gain
    • Abdominal pain
    • Jaundice (yellowing of the skin and whites of the eyes)
    • Vomiting blood
    • Sweating
    • Rapid heart rate
    • Anxiety
    • Headache
    • Convulsions
    • Loss of consciousness
    • Clouding of vision
    • Inflamed mouth and tongue
    • Abdominal mass or lump
  • Neuroendocrine Carcinoma

    • High blood sugar (hyperglycemia), which increases urination, thirst and hunger
    • Low blood sugar (hypoglycemia), which causes fatigue, nervousness, shakiness, dizziness, light-headedness, sweating, seizures and fainting
    • Diarrhea
    • Focused, persistent pain
    • Appetite loss
    • Persistent cough or hoarseness
    • Lumps
    • Changes in bowel or bladder habits
    • Unexplained weight gain or loss
    • Jaundice (yellowing of the skin and whites of the eyes)
    • Unusual bleeding or discharge
    • Persistent fever or night sweats
    • Headache
    • Anxiety
    • Ulcers
    • Skin rash

Just because someone has these symptoms doesn’t necessarily mean they have cancer. A doctor can diagnose the cause of symptoms.

Risk factors

While the cause of most neuroendocrine tumors is not yet known, some cases are tied to genetic conditions passed down through families. These include:

  • Multiple Endocrine Neoplasia Type 1 (MEN1) 
  • Multiple Endocrine Neoplasia type 2 (MEN2) 

There are also several factors that could increase anyone’s chances of developing a neuroendocrine tumor:

  • Age - Some neuroendocrine tumors tend to show up at certain ages, including pheochromocytoma (between 40 and 60), Merkel cell cancer (older than 70), appendix carcinoid tumors (around 40), lung carcinoid tumors (between 45 and 55) and other carcinoid tumors (between 55 and 65).
  • Gender - Men are more likely to develop pheochromocytoma and Merkel cell cancer than women.
  • Stomach Problems - Other diseases that damage the stomach and limit acid production can increase the risk of a stomach carcinoid tumo
  • Race/ethnicity - White people are more likely to develop Merkel cell cancer, while gastrointestinal carcinoid tumors are more common among black people (with black men at greater risk than black women). 
  • Weakened Immune System - People with HIV or who take medications to suppress their immune system after organ transplantation are at greater risk of developing a neuroendocrine tumor.
  • Arsenic Exposure - Arsenic exposure may increase the chance of getting Merkel cell cancer.
  • Sun Exposure - Doctors believe leaving the skin unprotected could increase the risk for Merkel cell cancer.


If a neuroendocrine tumor seems like a possibility, a physician will take all the steps necessary to ensure an accurate diagnosis. Tests depend on the type of tumor suspected and could include: 

  • Physical Exam (all tumor types) - A doctor feels for lumps and other signs of disease.
  • Blood and Urine Tests (Carcinoid, Pancreatic, Pheochromocytoma) - A doctor measures the amount of hormones and other substances present.
  • Molecular Testing (all tumor types) - A doctor tries to identify genes, proteins and other factors unique to the tumor.
  • Endoscopy (Carcinoid) - The doctor threads a thin tube (endoscope) with a camera and a light through the mouth and into the stomach and small intestine.
  • Colonoscopy (Carcinoid) - The doctor inserts a thin tube with a camera and light through the anus and into the colon.
  • Endoscopic Ultrasound (Carcinoid, Pancreatic) - The doctor guides a radio wave-emitting probe from the mouth into the upper part of the GI tract.
  • Biopsy (Carcinoid, Pheochromocytoma, Merkel cell, Neuroendocrine Carcinoma) - Removes cells or tissue to be examined under a microscope.
  • X-ray (all tumor types) - A small, safe amount of electromagnetic radiation helps create a picture of the body. 
  • Barium X-ray (Carcinoid) - Before the doctor takes X-rays, the patient swallows a liquid with barium or receives a barium enema to coat the esophagus, stomach and intestines.
  • Bone Scan (Carcinoid) - A radioactive (but safe) substance is injected in the veins and gathers in the bones, where a special camera can then detect damaged areas. 
  • Octreotide Scan (Carcinoid, Pancreatic) - A small, safe amount of a radioactive drug called octreotide is injected in a vein, with pictures then taken with a special camera.
  • CT (CAT) Scan (all tumor types) - X-rays are overlapped from different angles, with dye sometimes injected into veins or swallowed to see delicate, tiny structures.
  • PET (Positron Emission Tomography) Scan (Carcinoid) - Glucose (sugar) is injected into the veins so a rotating scanner can look for malignant cells throughout the body.
  • MRI (Magnetic Resonance Imaging) (all tumor types) - A magnet, radio waves and a computer take detailed pictures of the inside of the body.

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