Somatostatinomas are a rare type of malignant tumor that grows in or around the pancreas. Doctors may also call them neuroendocrine tumors (NET) or islet cell tumors. These tumors secrete large amounts of the hormone somatostatin.
Approximately 75% of somatostatinomas are cancerous. The most common symptoms of somatostatinomas are abdominal pain and unexplained weight loss. These symptoms rarely appear in the early stages.
Somatostatinomas are curable with surgery. During the surgery, a surgeon will remove the tumor entirely. Early diagnosis is key as the surgery becomes more complicated if the cancer has spread.
In this article, we review in more detail the symptoms, causes, and treatment of somatostatinomas and the outlook for people with this tumor.
NETs begin in the specialized cells of the neuroendocrine system. These cells produce hormones and play a role in a number of the body’s functions.
NETs can develop in any part of a person’s body but commonly exist in the:
- gastrointestinal tract
Somatostatinomas are a
Somatostatinomas are slow-growing tumors. The symptoms are nonspecific, which means that they resemble those of other common medical problems.
Additional signs and symptoms of somatostatinomas depend on the location of the tumor, which may be in the pancreas or the small intestine.
Somatostatinomas in the pancreas will
Somatostatin helps keep all of the gastrointestinal hormones in balance by blocking their secretion when necessary. Two examples of these hormones are insulin and gastrin.
In less than
- diabetes (high blood sugar)
- steatorrhea (greasy, fatty, and difficult-to-flush stools)
- cholelithiasis (gallstones)
Somatostatinomas in the duodenum do not cause somatostatinoma syndrome. These tumors can cause no symptoms at all, but if the tumor grows, it may cause symptoms to develop.
The tumor can spread to the liver and nearby lymph nodes. This may result in a blockage in parts of the intestines or gallbladder tubes.
This obstruction could lead to symptoms
- bloody diarrhea
- jaundice of the skin or whites of the eyes
- a painful and swollen belly
Somatostatinomas are the result of excess delta cells. However, the cause of this overgrowth remains unknown. It can occur in anyone, with or without a history of cancer in the family.
There are several
- Genetics: A gene mutation or abnormality can pass down from a parent to a child.
- Age: Most somatostatinomas are slow-growing and occur in individuals over the
age of 50.
- Smoking: Any history of smoking can increase a person’s chance of developing a neuroendocrine tumor of the pancreas.
- Alcohol: Heavy drinking may increase the risk of somatostatinoma growth.
- Pancreatitis: Experts have associated chronic inflammation of the pancreas with an increased risk of somatostatinomas.
- Diabetes: Somatostatinomas are more common in people who have type 2 diabetes.
The vague nature of somatostatinoma symptoms makes these tumors difficult to diagnose. This can delay diagnosis for many months to several years. Doctors usually find somatostatinomas when diagnosing unexplained abdominal pain, weight loss, blood loss, or diarrhea.
A somatostatinoma diagnosis may also occur after a pancreatic cancer surgery biopsy.
Diagnostic tests for somatostatinomas include:
- Blood tests: During blood tests, a person with somatostatinomas can show elevated somatostatin hormone levels. A doctor may then order an imaging test to look for the tumor and confirm the diagnosis.
- Computerized tomography (CT) scan: During this procedure, a doctor passes a number of beams of radiation through the person’s body. These beams can produce a detailed image of structures in the body to see if a tumor is present. CT scans can provide a 2D image of a “slice” of the body or a 3D image.
- Magnetic resonance imaging (MRI) scan: An MRI scan uses a strong magnetic field and radio waves to create images. MRI scans can create detailed images of organs and other tissues within the body that a doctor can use to see if a tumor is present. MRI scans differ from CT scans and X-rays as they do not use potentially harmful radiation.
- Endoscopic ultrasound: During this procedure, a doctor inserts a thin tube into the mouth and down into the first part of the small intestine. The tube has a small ultrasound probe that emits sound waves that bounce off the surrounding structures. The probe then recaptures these waves and produces an image of the surrounding area that a doctor can use to see if a tumor is present and make a diagnosis.
- Somatostatin receptor scintigraphy: During this test, a doctor
injectsradioactive octreotide, a drug similar to somatostatin, into the person’s veins. This drug attaches itself to tumor cells that have receptors for somatostatin. A radiation-measuring device can then detect the radioactive octreotide and creates images showing where the tumor cells are.
How they differ from VIPomas
VIPomas are another rare type of pancreatic cancer. They usually develop in the pancreas but may also be in the duodenum. People with VIPomas
VIP blocks the release of hydrochloric acid in the gastric juices, which causes problems with digesting food. As a result, people with VIPomas have frequent and large amounts of watery diarrhea.
Doctors usually recommend managing VIPomas with somatostatin analogs.
The only way to cure a somatostatinoma is to remove it completely with surgery. The extent of surgery depends on the size of the tumor and its location in the pancreas. The procedure may just involve the removal of a localized tumor.
If the tumor has spread, it may require a more extensive surgical procedure known as a Whipple procedure. This surgery removes the head of the pancreas, duodenum, gallbladder, bile duct, and lymph nodes.
If complete removal of the tumor is not possible, there are some additional treatment options. These include:
- a procedure called ablation, which uses extreme heat or cold to destroy small tumors
- somatostatin analog medications to slow down hormone production and shrink the tumor
- chemotherapy or specific medications to treat cancer that has spread
- a type of treatment called molecular targeted therapy, which uses drugs or other substances to identify the cancer cells and attack only them
Somatostatinoma symptoms are vague and can resemble those of many different medical conditions. They may come and go over several months or years.
Any individual who experiences unexplained weight loss, jaundice, abdominal pain, poor appetite, diarrhea, or greasy bowel movements should see a doctor.
Somatostatinomas make up
A person’s outlook will depend on their overall health and the extent of the tumor. If the tumor has not yet spread, surgery offers the best chance of a complete recovery.
The 10-year survival rate for pancreatic somatostatinoma is about
People with somatostatinomas also tend to have a better outlook than those with other types of pancreatic cancer.
Somatostatinomas are a rare type of tumor that grow in or around the pancreas. Doctors may also refer to these tumors as neuroendocrine tumors or islet cell tumors.
Symptoms include a loss of appetite, nausea and vomiting, abdominal pain, diarrhea, and unintentional weight loss.
Certain factors may increase a person’s risk of developing somatostatinomas, including genetics, increased age, smoking, alcohol consumption, pancreatitis, and diabetes.
A doctor may use blood tests or imaging tests to diagnose the tumors.
The most common treatment is the surgical removal of the tumors. A person’s outlook depends on their overall health, the size of the tumor, and whether the tumor has spread.
The 10-year survival rate for pancreatic somatostatinoma is about 72%.