REVIEW OF PANCREATIC ENDOCRINE NEOPLASMS
In the adult pancreas, pancreatic islets comprise approximately less than 2% of the overall pancreatic mass. Beta cells (insulin)constitute approximately 70% of the islet cell mass and are located centrally within the islet. [ Beta cells (70%) >> Alpha cells - Glucagon (10%) > D cells - Somatostatin (5%) > D2 cells- VIP > F cells-Pancreatic polypeptide ]. B and D cells are concentrated in the body and tail of the pancreas and F cells are concentrated in the head and uncinate process.
MC NET of Pancreas: Non-functional (Mostly malignant) >Insulinoma. www.pgmeeuploads.com
MC functioning NET of the pancreas = Insulinoma.
MC benign NET of Pancreas = Insulinoma
MC malignant functional NET of Pancreas = Gastrinoma
 Location of Insulinoma = 97% in pancreas (equal distribution in the head, body, and tail) > 3% in duodenum, splenic hilum, or gastrocolic ligament.
 Location of Gastrinoma = MC site is duodenum (50-70%) followed by Pancreas (20-40%) [ NOTE : In Duodenum, MC in 1st part (71%) >2nd part (21%) >3rd part (8%)]
ALSO KNOW : About 70-90% of gastrinomas are located within the Passaro’ triangle. www.pgmeeuploads.com
 MC site of glucagonoma: Body and tail of pancreas.
 MC site of VIPoma is tail of pancreas.
 MC site of somatostatinoma is head of the pancreas.
 MC site of NON FUNCTIONAL pancreatic NET = mostly in the head
 Unlike most endocrine pancreatic tumors, the majority (90%) of insulinomas are benign and solitary, and only 10% are malignant.
 Approximately 25- 50% of gastrinomas metastasize to lymph nodes or the liver, and are therefore considered malignant.
 Glucagonomas are malignant in 50-70 % of cases.
 More than two thirds of VIPomas are malignant and at the time of presentation more than 70% of patients have metastatic disease
 75-90 percent of somatostatinoma are malignant, with metastases to the liver or lymph nodes commonly noted at the time of diagnosis.
 More than Two thirds of nonfunctional pancreatic endocrine tumors [PPomas ] are malignant.
So Pancreatic NET with [ www.pgmeeuploads.com]
Most malignant Potential = Somatostatinoma
Least malignant potential = Insulinoma
Neoplasms of the Endocrine Pancreas - Case Scenarios !
 Pancreatic NET with symptomatic fasting hypoglycemia, a documented serum glucose level <50 mg/dL, and relief of symptoms with the administration of glucose ( ie Whipple Triad) = INSULINOMA
 Pancreatic NET with Peptic ulcers in unusual locations such as the jejunum = when intractable jejunal ulcers are found = Zollinger-Ellison syndrome [ GASTRINOMA] should be considered. www.pgmeeuploads.com
 Pancreatic NET with Severe intermittent watery diarrhea leading to dehydration, and weakness from fluid and electrolyte losses = Vasoactive Intestinal Peptide-Secreting Tumor
[The vasoactive intestinal peptide-secreting tumor(VIPoma) syndrome is also called the WDHA syndrome due to the presence of watery diarrhea, hypokalemia, and achlorhydria]
NOTE : At the time of diagnosis, 21% of patients with gastrinoma also have diarrhea but it is not severe as VIPoma.
 Pancreatic NET presenting with gallstones+ diabetes + and steatorrhea = Somatostatinoma. www.pgmeeuploads.com
[ Because somatostatin inhibits pancreatic and biliary secretions, patients with a somatostatinoma present with gallstones due to bile stasis, diabetes due to inhibition of insulin secretion, and steatorrhea due to inhibition of pancreatic exocrine secretion and bile secretion.] www.pgmeeuploads.com
 Pancreatic NET presenting with syndrome consisting of mild diabetes mellitus, a characteristic skin rash (necrolytic migratory erythema), and anemia = Glucagonoma = Hyperglycemic Cutaneous Syndrome
NOTE = Classic presentationof the 4Ds: Diabetes, dermatitis, DVT, and depression.
Necrolytic erythema migrans are MC manifestations of the disease, seen in 2/3rd of patients.
Deep vein thrombosis occurs in 30% of patients.
 Neurotensinoma = hypokalemia, weight loss, hypotension, cyanosis,
flushing and diabetes.
 Patient presents with acromegaly and a pancreatic
mass = GRFoma. GRFoma is a type of pancreatic endocrine tumor that hypersecretes growth hormone-releasing factor (GRF or GHRH)
 ASSOCIATION WITH MEN 1
Pancreatic NET is 2nd MC manifestation in MEN I [ Most Common is Parathyroid Adenoma ]
Nonfunctioning or that secrete pancreatic polypeptide are MC pancreatic NET in MEN-1.
MC functional NET in patients with MEN-1 is gastrinoma followed by insulinoma.
MC increased pancreatic hormone: Pancreatic polypeptides >Gastrin>Insulin.
NOTE : It is now recognized that the spectrum of this disease extends beyond the 3Ps. The duodenum is the most common site of gastrinomas in individuals with MEN-1(far in excess of the frequency of pancreatic gastrinomas), and synchronous duodenal and pancreatic tumors may be present in the same individual. [Robbins & Cotran Pathologic Basis of Disease 9th Edition page1136] www.pgmeeuploads.com
So MC functional NET in patients with MEN-1 is gastrinoma whereas most common site of gastrinomas in individuals with MEN-1 is duodenum.
 Nonfunctional pNET is a misnomer in the strict sense because those tumors frequently ectopically secrete a number of peptides. Most commonly Pancreatic polypeptide > Neurotensin. However thses do not cause specific syndromes and effect is due to tumor perse. Because a large proportion of nonfunctional pNETs (60-90%) secrete PP these tumors are often referred to as PPomas
[Ref : Sabiston Textbook of Surgery - The Biological Basis of Modern Surgical Practice, 19E page 944]
[Ref : Schwartz's Principles of Surgery, 10th Edition]
[Ref : Robbins & Cotran Pathologic Basis of Disease 9th Edition page1136]