Islet Cell Carcinoma (Endocrine Pancreas)
Gastrointestinal (GI) Oncology Program
Description
What is islet cell cancer?
Islet cell cancer, a rare cancer, is a disease in which cancer (malignant)
cells are found in certain tissues of the pancreas. The pancreas is about 6
inches long and is shaped like a thin pear, wider at one end and narrower at
the other. The pancreas lies behind the stomach, inside a loop formed by part
of the small intestine. The broader right end of the pancreas is called the
head, the middle section is called the body, and the narrow left end is the
tail.
The pancreas has two basic jobs in the body. It produces digestive juices that
help break down (digest) food, and hormones (such as insulin) that regulate how
the body stores and uses food. The area of the pancreas that produces
digestive juices is called the exocrine pancreas. About 95% of pancreatic
cancers begin in the exocrine pancreas. The hormone-producing area of the
pancreas has special cells called islet cells and is called the endocrine
pancreas. Only about 5% of pancreatic cancers start here. This summary has
information on cancer of the endocrine pancreas (islet cell cancer). (Refer to
the PDQ summary on Pancreatic Cancer Treatment for more information on cancer
of the exocrine pancreas.)
The islet cells in the pancreas make many hormones, including insulin, which
help the body store and use sugars. When islet cells in the pancreas become
cancerous, they may make too many hormones. Islet cell cancers that make too
many hormones are called functioning tumors. Other islet cell cancers may not
make extra hormones and are called nonfunctioning tumors. Tumors that do not
spread to other parts of the body can also be found in the islet cells. These
are called benign tumors and are not cancer. A doctor will need to determine
whether the tumor is cancer or a benign tumor.
A doctor should be seen if there is pain in the abdomen, diarrhea, stomach
pain, a tired feeling all the time, fainting, or weight gain without eating too
much.
If there are symptoms, the doctor will order blood and urine tests to see
whether the amounts of hormones in the body are normal. Other tests, including
x-rays and special scans, may also be done.
The chance of recovery (prognosis) depends on the type of islet cell cancer the
patient has, how far the cancer has spread, and the patient’s overall health.