Pancreatic neuroendocrine neoplasms
109,696views
00:00 / 00:00
Flashcards
Pancreatic neuroendocrine neoplasms
of complete
Questions
USMLE® Step 1 style questions USMLE
of complete
Memory Anchors and Partner Content
External Links
Transcript
Content Reviewers
With pancreatic neuroendocrine neoplasms, neuroendocrine refers to pancreatic cells which release hormones in response to signals from the nerves, and neoplasm refers to a cancer.
So, pancreatic neuroendocrine neoplasm is a cancer of neuroendocrine cells that are within the pancreas.
They can also be called pancreatic neuroendocrine tumors, or just panNETs for short.
In addition to endocrine cells, the pancreas also has exocrine cells, which make up a majority of the gland.
Most pancreatic cancers arise from exocrine cells and they’re called adenocarcinomas, whereas only a minority arise from panNETs.
The pancreas is a long, skinny gland the length of a dollar bill which sits to the left of the duodenum and behind the stomach, in the upper abdomen, or the epigastric region.
It plays two main roles - there’s the exocrine part of the pancreas which has acinar cells that make digestive enzymes that are secreted into the duodenum to help digest food.
There’s also the endocrine part of the pancreas which has a few different types of islet cells, or neuroendocrine cells, each of which make different hormones.
These neuroendocrine cells are present in clusters, or islands, called islets of Langerhans.
The largest group of cells are the beta (β) cells which secrete insulin.
Insulin mainly lowers the blood glucose levels by transporting glucose into the cells, and also pushes potassium into cells, which decreases potassium in the blood.
Another group are the alpha (α) cells which secrete glucagon, a hormone that does exactly the opposite of insulin, it raises the blood glucose levels by getting the liver to generate glucose from amino acids and lipids, and to break down glycogen into glucose.
There are also Delta cells which secrete somatostatin, which decreases the release of other hormones, including insulin, glucagon, and serotonin.
There are also pancreatic polypeptide cells, which secrete pancreatic polypeptide, which stimulates the release of digestive enzymes from the stomach and small intestine, and slows down intestinal movement.
Finally, there are a few rare cell types called enterochromaffin cells, D1 cells, and G cells, which are scattered in the islets of Langerhans.
Summary
Pancreatic neuroendocrine Tumors (PNETs) are a type of tumor that arises in the endocrine tissue of the pancreas. These tumors include insulinomas, gastrinoma, glucagonoma, and VIPomas, and secrete hormones including insulin, gastrin, glucagon, and vasoactive intestinal peptide respectively. Symptoms of PNETs may include abdominal pain, weight loss, and changes in bowel habits. Treatment options may involve drugs like somatostatin and surgery.
Sources
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
- "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
- "The Pathologic Classification of Neuroendocrine Tumors" Pancreas (2010)
- "Update on pancreatic neuroendocrine tumors" PubMed (2014)