Neuroendodcrine Tumors

Question 1

What does the term MEN (multiple endocrine neoplasms) apply to?

Answer 1

when two or more endocrine glands are affected.

Question 2

What are MEN syndromes?

Answer 2

Conditions which cause overactivity and enlargement and tumors of certain endocrine glands. Usually inherited.

Question 3

Describe the classification of MEN syndromes?

Answer 3

MEN 1 = parathyroid tumors, pancreatic tumors, pituitary tumors. MEN 2a = medullary thyroid cancers, pheochromocytoma, parathyroid. MEN 2b = Medullary thyroid cancers, pheochromocytoma, neuromas

Question 4

What is the epidemiology of MEN 1?

Answer 4

rare, occurs equally in M/F and all ethnic groups. symptoms often don’t develop until >30yrs

Question 5

Describe the progression of MEN 1

Answer 5

usually first develop over-activity of the parathyroid than overproduction of gastrin and insulin by the pancreas. pituitary adenomas occur in 42%

Question 6

Who should be tested for MEN1 and what are the tests?

Answer 6

People who have over-activity of 2 or more of the glands involved in MEN. Typically benign tumors. Genetic testing of chromo 11 and 13. Screen for overactivity of parathyroid- Ca+, PTH, prolactin, gastrin

Question 7

What is the progression of MEN2a?

Answer 7

Will almost certainly develop medullary thyroid cancer. Very aggressive, begins early in life and grows quickly. should have their thyroid surgically removed before mid teen years

Question 8

What is the testing for MEN2a?

Answer 8

genetic testing – ret protooncogene mutation. screen for early signs of medullary cancer-pentagastrin testing looking for raised levels of calcitonin, urinary catecholamine, Ca+, and PTH levels

Question 9

What is Marfonoid Habitus seen in patients with MEN 2b?

Answer 9

Arachnodactyly- long fingers and extremities. tall with disproportionately long legs and arms. spondylolisthesis, scoliosis

Question 10

How do you test for MEN2b?

Answer 10

same as for MEN 2a except no screening for parathyroid abnormalities

Question 11

What is an insulinoma?

Answer 11

beta-cell tumor that secretes insulin. Hyperinsulinemia – not responsive to falling glucose concentrations in the fasting state – result is persistent hypoglycemia. More common in women >50yrs

Question 12

What are symptoms associated with insulinoma?

Answer 12

blurred vision/diplopia, HA, slurred speech, weakness, psychotic behavior, convulsions, coma

Question 13

What is the diagnostic testing for an insulinoma?

Answer 13

72-hour monitored fast- if glucose levels fall to less than 40 mg/dL while insulin levels are more than 20 U/mL. Insulin to glucose ratio is greater than 0.4. Increased levels of C peptide and pro-insulin.

Question 14

What is the treatment for an insulinoma?

Answer 14

surgical resection of pancreas. meds: Diazoxide or octreotide (both inhibit secretion of insulin), or continuous SQ glucagon. Streptozotocin for malignant insulinoma

Question 15

What is a gastrinoma (Zollinger-Ellison Syndrome)?

Answer 15

Tumor of pancreas or duodenum that produces excess levels of gastrin. 25% are part of MEN-1 syndrome

Question 16

What are the symptoms of gastrinoma (Zollinger-Ellison Syndrome)?

Answer 16

peptic ulcers with absence of h-pylori or NSAID consumption. Duodenojejunitis. Esophagitis. Refractory diarrhea. Multiple duodenal ulcers

Question 17

What tests are done to diagnose gastrinoma (Zollinger-Ellison Syndrome)?

Answer 17

Fasting gastrin. Look for results to be >1000.
If gastrin is >200 and <1000, then do Positive Secretin Provacation test. gastrinoma will demonstrate a paradoxical increase of 100 to 200 pg/mL in serum gastrin

Question 18

What is a somatostatin receptor scintigraphy?

Answer 18

radioactive octreotide is injected into a vein attaches to tumor cells that have receptors for somatostatin. A device detects the radioactive octreotide, and makes pictures showing where the tumor cells are

Question 19

What is treatment for a gastrinoma (Zollinger-Ellison Syndrome)?

Answer 19

High Doses of Proton pump inhibitors. Surgical removal of gastinoma

Question 20

What is a VIPoma (Verner-Morrison Syndrome)?

Answer 20

Pancreatic neoplasm secreting vasoactive intestinal polypeptide in the tail of the pancreas

Question 21

What is the function of the vasoactive intestinal peptide (VIP)?

Answer 21

relax certain muscles along the gastrointestinal tract. increases the amount of water and electrolytes released from the pancreas and gut. triggers the release of hormones from the pancreas, gut, and hypothalamus. blocksgastrinandgastric acid release

Question 22

What is the presentation of a VIPoma?

Answer 22

Severe, intermittent, watery diarrhea—> decreased gastrin, large amts of K+ in stool, fluid/electrolyte losses. Flushing

Question 23

What labs are used to diagnose VIPoma?

Answer 23

Serum VIP levels (nl levels=75-190 pg/mL), CT scans, ultrasound imaging

Question 24

What are the treatment options for VIPoma?

Answer 24

correct fluid loss and electrolyte imbalances. Somatostatin analogs to control diarrhea. Surgical resection

Question 25

What is a glucagonoma?

Answer 25

Pancreatic Islet Cell tumor that secretes glucagon. Increases levels of glucose in blood. Produces a distinctive rash. Most are malignant and occurs in women

Question 26

What is a necrolytic migratory erythema?

Answer 26

characteristic of glucagonoma. begins as erythematous papules or plaques. lesions enlarge and coalesce. Central clearing leaving bronze-colored indurated areas, with blistering, crusting, and scaling at the borders. painful and pruritic

Question 27

What tests are done to diagnose glucagonoma and how is it treated?

Answer 27

Serum glucagon level >500 pg/ml. Imaging to identify tumor location. Surgical resection and zinc ointment for skin rash

Question 28

What are the most common locations for a carcinoid tumor?

Answer 28

Midgut: Ileum, Jejunum, Right Colon, Appendix

Question 29

What are signs and symptoms of carcinoid tumors?

Answer 29

Periodic abdominal pain, episodic flushing, diarrhea/malabsorption

Question 30

How are carcinoid tumors diagnosed?

Answer 30

Radiography (Upper/Lower GI series w/ contrast), CT, Octreoscan, MRI, Colonoscopy, Histology

Question 31

How are carcinoid tumors treated?

Answer 31

Surgically, Appendectomy, Block resection w/ adjacent lymph nodes. Medically with chemo or palliatively with ocreotide