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NewYork-Presbyterian/Weill Cornell Medical Center - Center for Advanced Digestive Care

Endocrine Tumors

The endocrine system consists of specialized glands that make and release hormones—or chemical messengers—directly into the bloodstream. They have a specific regulatory effect on numerous body functions, such as activities of entire organs; growth and development; reproduction; sexual characteristics; usage and storage of energy; or levels of fluid, salt and sugar in the blood.

An endocrine tumor is an abnormal growth that arises from glandular cells that produce these hormones. The tumor itself can also produce hormones on its own in excessive amounts and cause serious illness. Some impair quality of life, while others have the potential to be life-threatening.

Endocrine tumors develop in many digestive organs, including the stomach, duodenum, small intestine, appendix, large intestine, rectum, liver, and pancreas, as well as other areas in the abdomen.

Carcinoid Tumors of the Digestive Tract

Carcinoid tumors are considered a type of endocrine tumor because they start in the hormone-producing cells of various organs—primarily the digestive tract. A carcinoid tumor is often a slow-growing endocrine cancer that can arise anywhere between the stomach and the rectum (the small intestine, appendix and stomach are common sites).

Because carcinoid tumors generally grow slowly over many years, patients typically don't experience symptoms—such as diarrhea, skin flushing, difficulty breathing—until they are quite advanced. The tumor might be discovered through a test for an unrelated disease or condition. These tumors can occur as part of certain genetic disorders such as multiple endocrine neoplasia type 1 (MEN I). and neurofibromatosis type 1 (NF1 or von Recklinghausen disease) a disorder affecting the nervous system. Carcinoid tumors account for nearly half of all small intestine cancers.

Symptoms: The symptoms a person develops from a gastrointestinal carcinoid tumor often depend on where it is located.

In about 1 out of 10 cases, carcinoid tumors release enough hormone-like substances into the bloodstream to cause symptoms known as carcinoid syndrome, that include facial flushing, severe diarrhea, wheezing, and fast heartbeat. Over a long period of time, these hormone-like substances can damage heart valves, causing shortness of breath, weakness, heart murmur. They may also cause weight gain, weakness, high blood sugar or diabetes, and increased body and facial hair.


Lab tests

If a carcinoid tumor is suspected and a patient has symptoms, blood and urine tests may be used to look for abnormal amounts of hormones and other substances produced by the tumor.


To confirm diagnosis, a small sample of the tumor may be obtained for examination under a microscope using either a thin needle (fine-needle aspiration biopsy) or a wider needle (core biopsy). Sometimes, doctors will suggest a biopsy in which the tumor and possibly other tissues in the area are removed by surgery, most often done under general anesthesia.


Imaging tests can help to confirm the diagnosis and determine the exact location and size of the tumor, including whether there has been spread to other organs, and whether the tumor(s) can be surgically removed.


The Center offers several leading-edge treatment options for patients with a gastrointestinal carcinoid tumor. Our multidisciplinary team of endocrine specialists works with patients to determine the best approach.

  • Surgery: Surgical removal of the tumor is usually the first treatment for gastrointestinal carcinoid tumors. When possible, our surgeons use image-guided minimally invasive laparoscopic surgical techniques to remove carcinoid tumors and nearby lymph nodes.
  • Liver Tumor Embolization: Embolization is a localized approach to destroying liver tumors that may be used to treat gastrointestinal carcinoid tumors that spread to the liver. Embolization uses image guidance, such as CT or ultrasound, to inject tiny particles through a small tube, or catheter, threaded into the hepatic artery. The particles block the flow of blood to the tumor, depriving it of the nutrients and oxygen it needs to survive. Embolization may be used alone or in combination with surgery.
  • Hormone Therapy: Patients with gastrointestinal carcinoid tumors that cannot be surgically removed may benefit from injections of a synthetic hormone which controls hormone-related symptoms and may have the potential to slow tumor growth.
  • Chemotherapy: Chemotherapy is usually reserved for patients whose carcinoid tumors begin to grow during treatment with a synthetic hormone. In addition, chemotherapy may be used to treat advanced carcinoid tumors that contain fast-growing cells.
  • Radiolabeled Therapy: Most carcinoid tumors bind somatostatin and thus these tumors may respond to a nuclear medicine technique called radiolabeled therapy, which selectively destroys tumor cells.

Pancreatic Endocrine Tumors

Pancreatic endocrine cancers are uncommon and arise in the insulin-producing cells of the pancreas called Islet cells. These tumors represent only 5 percent of pancreatic tumors and tend to be treatable, slow-growing tumors. (The vast majority of tumors found in the pancreas arise from ducts and are called adenocarcinomas—what is commonly called pancreatic cancer.) Pancreatic endocrine tumors that grow without producing hormones are called non-functioning tumors. Tumors that secrete hormones into the bloodstream are called functional tumors.

Functional Tumors (Hormone-producing)

These tumors secrete hormones directly into the bloodstream and lead to dramatic hormone-related symptoms and metabolic imbalances. They tend be very small—only a few millimeters in size—when the patient presents with significant symptoms and for this reason often may be localized to the pancreas.


A rare type of pancreatic tumor that produces excessive amounts of insulin, causing low blood sugar. Insulinomas are more common in women and usually small (less than 2cm). More than 90% of insulinomas are benign.

Symptoms result from low blood sugar and include: faintness, weakness, trembling, heart palpitations, sweating, hunger, anxiety, headache, confusion, dizziness—and sometimes even convulsions, loss of consciousness, seizures.


A tumor usually arising in the pancreas or duodenum (the first segment of the small intestine) that produces excessive levels of the hormone gastrin. Gastrin stimulates the stomach to secrete large amounts of acid, causing peptic ulcers. This condition is called Zollinger-Ellison syndrome. Most gastrinomas are malignant.

Symptoms: Ulcers of the small intestine or stomach, diarrhea, stomach pain, bleeding, nausea, vomiting, weakness, fatigue, unexplained weight loss or gain.


A small, slow-growing, benign or malignant tumor that sometimes overproduces serotonin or other hormones.

Symptoms: Facial flushing, diarrhea, abdominal pain, asthma, rash, and dark-colored stools (indicating intestinal bleeding).

Rare Tumors

These tumors are malignant in the vast majority of patients and may present as large tumors at the time of diagnosis.


This tumor produces excessive amounts of VIP (vasoactive intestinal polypeptide) a hormone which helps control the secretion and absorption of water in the intestines, leading to severe diarrhea, dehydration, weight loss, metabolic disturbances and electrolyte imbalances.

Symptoms: Prolonged, severe watery diarrhea, low potassium, acidic blood, muscular weakness, nausea, vomiting, abdominal pain.


A somatostatinoma secretes excessive amounts of a hormone called somatostatin, a chemical that acts as a neurotransmitter. This tumor typically develops in the head of the pancreas and disrupts the production of a variety of hormones, leading to diabetes, gallstones and an inability to digest fats.

Symptoms: Weight loss, diabetes mellitus, gallbladder disease, low levels of hydrochloric acid in the stomach which causes poor digestion, diarrhea and fat in the feces.


This tumor produces excessive amounts of glucagon, a hormone that reduces insulin production causing an elevation of blood sugar and diabetes.

Symptoms: Weight loss, brownish red skin rash (starts at the groin and moves to buttocks, forearms, legs), bright, red-orange tongue, cracks at corners of mouth.

Non-functioning Tumors (Produce No Hormones)

These tumors make up the majority of pancreatic Islet cell tumors. Because they do not release any hormones into the blood that can cause symptoms, they grow silently for a long time before they are discovered, typically at more advanced stages of disease when the tumor becomes big enough to push against other structures. They may cause obstructive symptoms of the biliary tract or duodenum, bleeding into the GI tract, or abdominal masses.

More than half of these non-functioning tumors are malignant (cancerous) at the time of diagnosis. They may account for as much as 60% of all endocrine tumors of the pancreas.

Symptoms: Abdominal mass, nausea, vomiting, abdominal pain, back pain, jaundice (from obstruction).


In addition to a physical examination, endocrine oncologists at the Center may use the following tests to diagnose an endocrine tumor:

Laboratory tests

Your doctor may take samples of blood, urine, and stool to check for abnormal levels of hormones, glucose levels, and other substances.

Neurological examination

Your doctor may test your reflexes, motor and sensory skills, balance and coordination, and mental status to evaluate your central nervous system.

Imaging tests

Imaging tests may be used to find out whether the cancer has spread and to pinpoint its location.

  • Computed tomography (CT or CAT) scan
  • Endoscopy
  • Colonoscope
  • Magnetic resonance imaging (MRI)
  • Positron emission tomography (PET scan)
  • Radionuclide scanning (OctreoScan)


The treatment of an endocrine tumor depends on the type of endocrine tumor, the size and location of the tumor, if it is cancerous, whether the cancer has spread, and the patient's overall health.

  • Surgery The purpose of surgery is to remove the entire tumor, along with some of the healthy tissue around it called a margin. We specialize in image-guided minimally invasive surgical approaches that reduce the length of inpatient hospital stays, result in less physical trauma, and help patients resume normal activities as soon as possible.
  • Chemotherapy Systemic chemotherapy, the use of drugs to kill cancer cells, is delivered through the bloodstream, targeting cancer cells throughout the body.
  • Radiation therapy Radiation therapy uses a certain type of energy called ionizing radiation to kill cancer cells and shrink tumors. The goal is to damage as many cancer cells as possible without harming healthy tissue.
  • Hormone therapy Hormone therapy may be given to help stop the tumor from growing, or to relieve symptoms caused by the tumor by lowering the levels of hormones in the body.
  • Immunotherapy (also called biologic therapy) This treatment is designed to boost the body's natural defenses to fight the cancer. It uses materials either made by the body or in a laboratory to bolster, target, or restore immune system function.
  • Targeted therapy This treatment targets faulty genes or proteins that contribute to cancer growth and development. Early results of clinical trials with targeted therapy agents are promising in the treatment of endocrine tumors, but additional research is needed to demonstrate their effectiveness.
  • Radiolabeled Therapy Most pancreatic tumors bind somatostatin and thus these tumors may respond to a nuclear medicine technique called radiolabeled therapy, which selectively destroys tumor cells.

Clinical Trials

NewYork-Presbyterian Hospital has established a clinical trials network to ensure that patients have access to medicines and therapies that are on the cutting edge. Clinical trials take place under the most stringent guidelines, and those who participate benefit from closely supervised monitoring. Patients are encouraged to talk to their doctors about current clinical trials for endocrine tumors when making treatment plan decisions. For more information, visit Clinical Trials.