A somatostatinoma is a rare type of neuroendocrine tumor that grows in the pancreas and sometimes the small bowel. A neuroendocrine tumor is one that is made up of hormone-producing cells. These hormone-producing cells are called islet cells.
A somatostatinoma develops specifically in the delta islet cell, which is responsible for producing the hormone somatostatin. The tumor causes these cells to produce more of this hormone.
When your body produces extra somatostatin hormones, it stops producing other pancreatic hormones. When those other hormones become scarce, it eventually leads to symptoms appearing.
The symptoms of a somatostatinoma usually start mild and increase in severity gradually. These symptoms are similar to those caused by other medical conditions. For this reason, it’s important that you make an appointment with your doctor to get a correct diagnosis. This should ensure proper treatment for any medical condition underlying your symptoms.
The symptoms caused by a somatostatinoma may include the following:
- pain in the abdomen (most common symptom)
- unexplained weight loss
- steatorrhea, or fatty stools
- bowel blockage
- jaundice, or yellowing skin (more common when a somatostatinoma is in the small bowel)
Medical conditions other than a somatostatinoma may be causing many of these symptoms. This is often the case, as somatostatinomas are so rare. However, your doctor is the only one who can diagnose the exact condition behind your specific symptoms.
What causes a somatostatinoma is currently unknown. However, there are some risk factors that may lead to a somatostatinoma.
This condition, which can affect both men and women, usually occurs after age 50. The following are some other possible risk factors for neuroendocrine tumors:
- a family history of multiple endocrine neoplasia type 1 (MEN1), a rare type of cancer syndrome that is hereditary
- von Hippel-Lindau disease
- tuberous sclerosis
Diagnosis must be made by a medical professional. Your doctor will usually start the diagnosis process with a fasting blood test. This test checks for an elevated somatostatin level. The blood test is often followed by one or more of the following diagnostic scans or X-rays:
- endoscopic ultrasound
- CT scan
- octreoscan (which is a radioactive scan)
- MRI scan
These tests allow your doctor to see the tumor, which may be either cancerous or noncancerous. The majority of somatostatinomas are cancerous. The only way to determine whether your tumor is cancerous is with surgery.
A somatostatinoma is most often treated by removing the tumor through surgery. If the tumor is cancerous and the cancer has spread (a condition referred to as metastasis), surgery may not be an option. In the case of metastasis, your doctor will treat and manage whatever symptoms the somatostatinoma may be causing.
Associated conditions and complications | Complications
Some of the conditions that are associated with somatostatinomas may include the following:
- von Hippel-Lindau syndrome
- neurofibromatosis type 1
- diabetes mellitus
Somatostatinomas are usually found at a later stage, which can complicate treatment options. In a late stage, cancerous tumors are more likely to have already metastasized. After metastasis, treatment is limited, because surgery usually isn’t an option.
Despite the rare nature of somatostatinomas, the outlook is good for the 5-year survival rate. When a somatostatinoma can be removed surgically, there is a nearly 100 percent survival rate five years following the removal. The five-year survival rate for those treated after a somatostatinoma has metastasized is 60 percent.
The key is to get a diagnosis as early as possible. If you have some of the symptoms of a somatostatinoma, you should make an appointment with your doctor as soon as possible. Diagnostic testing will be able to determine the specific cause of your symptoms.
If your doctor determines you have a somatostatinoma, then the earlier you begin treatment, the better your prognosis will be.