Pancreatic neoplasms Flashcards
1
Q
Abnormal pancreatic islet histology
A
- Most pancreatic neoplasms look similar: cords and nests of well-differentiated cells that are not distinguishable from cells of normal islets
- However they show immunocytochemistry and/or electron microscopy changes that indicate neoplasia
- Neoplasms can be functional (secreting the normal hormone at increased amounts) or non-functional (not secreting the hormone)
- Most often mets to liver
2
Q
Insulinoma
A
- A beta cell tumor comprises about 1/2 of all islet cell neoplasms
- Dx via high levels of circulating insulin and C peptide during a bout of hypoglycemia
- Only 10% are malignant
3
Q
Gastrinoma (zollinger-ellison syndrome)
A
- A tumor of G cells that comprises 1/4 of islet cell neoplasms
- G cells produce gratin, thus there is hyper secretion of gastrin which induces continuous secretion of gastric acid by the stomach
- This results in peptic ulcers that may involve the duodenum and jejunum
- May lead to difficulty absorbing fat, leading to steatorrhea (fat in stool) and diarrhea
- Gastrinomas can also be found in duodenum
- > 50% are malignant
4
Q
Multiple endocrine neoplasia (MEN)
A
- Syndromes that are infrequent, familial, and characterized by a variety of endocrine organ dysfxn
- MEN type 1 (wermer syndrome): includes pituitary adenoma, parathyroid adenoma and pancreatic islet adenoma (usually gastrinoma)
- Pts usually present w/ zollinger-ellison syndrome
- MEN type 2A (sipple syndrome): medullary CA of thyroid, adrenal medullary hyperplasia, parathyroid adenoma
- These pts usually present w/ paroxysmal HTN and hyperparathyroidism
- MEN type 2B (william syndrome): also involves thyroid and adrenal neoplasms (like type 2A), but together w/ mucocutaneous neuromas (seen in skin, oral cavity/lips, GI tract, bronchi, eye lids)
- Genetic basis for both type 2A and 2B is mutations of the RET gene
