What Is a Pancreatic Neuroendocrine Tumor?
Islet cell tumors, also known as pancreatic neuroendocrine tumors (NETs), are a kind of cancer that begins in the pancreas. (Cancer begins when the body's cells begin to grow out of control.) See What Is Cancer?) for additional information on how cancers begin and spread.
Pancreatic NETs are a kind of pancreatic cancer that is less prevalent. They account for less than 2% of pancreatic cancer cases, although they have a better prognosis than the more frequent kind.
What causes pancreatic neuroendocrine tumors to develop?
Neuroendocrine tumors in the pancreas begin in neuroendocrine cells, a kind of cell present in the pancreas. Neuroendocrine cells can be found in different parts of the body, however pancreatic neuroendocrine tumors are malignancies that arise from neuroendocrine cells in the pancreas.
The neuroendocrine system
The neuroendocrine system is a mechanism that regulates hormones in the body.
In some aspects, neuroendocrine cells resemble nerve cells, while in others, they resemble hormone-producing endocrine cells. Organs are not formed by the cells in this system. Instead, they're strewn over the esophagus, stomach, pancreas, intestines, and lungs, among other organs.
In the pancreas, neuroendocrine cells (also known as endocrine cells) are located in tiny clusters called islets (or islets of Langerhans). Important chemicals like insulin and glucagon (which help manage blood sugar levels) are produced in these islets and released straight into the bloodstream.
The pancreas
The pancreas is a gland located in the abdomen.
The pancreas is a digestive organ found behind the stomach. With a wide head, tapering body, and narrow, pointed tail, it resembles a fish. It's around 6 inches (15 centimeters) long in adults, but only about 2 inches (5 centimeters) broad.
The head of the pancreas is located behind where the stomach joins the duodenum on the right side of the abdomen (belly) (the first part of the small intestine).
The pancreas' body is located behind the stomach.
The pancreas' tail is located adjacent to the spleen on the left side of the belly.
Neuroendocrine cancers begin in the pancreas' endocrine cells. However, exocrine cells, which make up the majority of the pancreas, are a different sort of cell. Exocrine glands and ducts are made up of these cells. Pancreatic enzymes are produced by the exocrine glands and released into the intestines to aid digestion (especially fats). Exocrine cells are the source of the most frequent kind of pancreatic cancer, adenocarcinoma of the pancreas. For more information on this type of cancer, see Pancreatic Cancer.
If you've been diagnosed with pancreatic cancer, it's critical to determine if it's an exocrine cancer (see Pancreatic Cancer) or an endocrine cancer (see Endocrine Cancer) (discussed here). They have diverse risk factors and causes, different signs and symptoms, different diagnostic tests, different treatments, and different prognoses.
Neuroendocrine tumors of the pancreas come in a variety of forms.
Grade of the tumor
The tumor grade of pancreatic neuroendocrine tumors (NETs) defines how rapidly the disease is expected to develop and spread.
- Grade 1: neuroendocrine tumors (also known as low-grade or well-differentiated tumors) have cells that resemble normal cells and do not proliferate rapidly.
- Grade 2: tumors (also known as intermediate-grade or moderately differentiated tumors) contain characteristics that are halfway between low- and high-grade cancers (see below).
- Grade 3: Neuroendocrine tumors (also known as high-grade or poorly differentiated) include cells that appear aberrant and grow quickly.
Pancreatic neuroendocrine tumors are cancers of the pancreas that are grade 1 or 2. These malignancies have a moderate growth rate and have the potential to spread to other regions of the body.
Pancreatic neuroendocrine carcinomas are cancers of the third grade (NECs). These malignancies develop and spread fast, and they have the potential to spread to other regions of the body.
Measuring how many cells are in the process of dividing into new cells is also an essential aspect of grading. Pancreatic Neuroendocrine Tumor Stages goes into much depth on this.
The role of the tumor
Pancreatic NETs are further classified as functional (producing hormones that induce symptoms) or non-functioning (not producing hormones) (not making hormones).
About half of pancreatic NETs produce hormones, which are released into the bloodstream and induce symptoms. These are referred to as functional NETs. Each one is called for the hormone that tumor cells produce.
- Insulinomas arise from insulin-producing cells.
- Glucagonomas are tumors that arise from cells that produce glucagon.
- Gastrinomas are tumors that develop from cells that produce gastrin.
- Somatostatin-producing cells give rise to somatostatinomas.
VIPomas are formed by cells that produce the vasoactive intestinal peptide (VIP).
ACTH-secreting tumors arise from adrenocorticotropic hormone-producing cells (ACTH).
Insulinomas make up the majority of functional NETs (up to 70%). The other categories are far less prevalent.
Non-functioning NETs: These tumors produce insufficient extra hormones to induce symptoms. They can grow fairly large before being discovered since they don't produce extra hormones that cause symptoms. When they reach a big size, they may experience abdominal (belly) discomfort, a loss of appetite, and weight loss.
Carcinoid tumors: These NETs are more frequent in other regions of the digestive system, while they can develop in the pancreas on rare occasions. Serotonin is frequently produced by these tumors.
Treatment and prognosis for pancreatic NETs vary depending on the kind of tumor and its stage (extent), although they have a better prognosis than pancreatic exocrine tumors.