Multiple Endocrine Neoplasia

Question 1

What is significant about the genetics of MENs?

Answer 1

autosomal dominant trait

high degree of penetrance

variable expressivity

Question 2

What is the prevalence of MEN syndromes?

Answer 2

MEN 1 = 2-20 per 100,000

MEN less common (2B = rarest, 5% of all type 2 cases)

Question 3

What types of cells do MEN tumors arise from?

Answer 3

Amine precursor uptake and decarboxylation (APUD) cells

make/secrete biogenic amines thru enzyme L-dopa decarboxylase

found in a lot of different organs

make small popypeptide hormones

membrane-bound neurosecretory granules

Question 4

What types of tumors are found in MEN 1 and what is their prevalence?

Answer 4

PT adenoma = 95%

pancreatic tumors = 50%

pit adenoma = 40%

carcinoid tumors = 30%

Question 5

what type of tumors only in MEN type 2?

Answer 5

medullary thy carcinoma = 100% in both a and b

pheochromocytoma = 50% of both a and b

Question 6

What tumors distinguish MEN 2A and 2B?

Answer 6

In both: medullary thy cancer, pheochromocytoma

Only in 2a: Parathyroid carcinoma

Only in 2B: neuromas

Question 7

What type of MEN has pancreatic and pituitary tumors?

Answer 7

MEN1

Question 8

What type of MENs have parathyroid adenomas?

Answer 8

MEN1

MEN2A

Question 9

What type of MEN has marfanoid habitus?

Answer 9

MEN 2B (100%)

Question 10

What is the genetic cause of MEN 1?

Answer 10

2 copies of mutated MEN1 –> encodes menin protein = tumor suppressor

mutation –> unregulated cell division –> tumor

Question 11

What is Wermer syndrome?

Answer 11

MEN type 1

Question 12

In what type of MEN are carcinoid tumors common?

Answer 12

type 1

males: common in thymus
women: bronchial

Question 13

What are the 3 means of diagnosing MEN 1?

Answer 13

clinical: 2 or more Men 1-associated tumors
familial: pt w/ one men tumor and 1st degree relative w/ men1
genetic: asymptomatic carrier of men1

Question 14

What is usually the first manifestation of MEN type 1?

Answer 14

hyperparathyroidism

PT gland tumors in 95% of cases –> hyperplasia of all four glands

Question 15

What is the second most common manifestation of men type 1?

Answer 15

cancer of pancreatic islet cells

most frequent = gastrinoma (1/3 of all gastrinomas assoc w/ MEN1)

insulinoma = 2nd most common –> hypoglycemia

Question 16

What type of men has pituitary tumors?

What type of tumor are they usually?

Answer 16

Men type 1 (~50% of cases)

prolactinoma most common kind

most of them are functionally active

Question 17

What is the treatment for MEN 1?

Answer 17

surgical resection of associated adenomas

or medication management of pituitary tumors (bromocriptine for prolactinoma)

subtotal pancreatectomy, but surgical cure for these tumors is usually not possible

Question 18

What is MEN type 2 caused by?

Answer 18

by 1 gain of fxn mutation in RET protooncogene

RET encodes for RTK that Piates and activates enzymes critical to cell development

Question 19

What is the most common sign of men 2?

Answer 19

medullary thyroid carcinoma =

transformation of parafolicular/C cells of thyroid –> detect high calcitonin

abt 50% also get pheochromocytoma

Question 20

Of the type 2 MENs, which is more severe?

Answer 20

type 2B

avg age of death is ~30

in type a avg age of death is ~60

Question 21

What is Sipple syndrome?

Answer 21

Men 2A

Question 22

What is distinct about the pheochromocytomas in MEN 2 vs sporadic types?

Answer 22

secrete greater amounts of epinephrine than sporadic type

Question 23

In what type of MEN is cutaneous lichen amyloidosis sometimes present?

Answer 23

type 2A

Question 24

What is distinct about the medullary TC in MEN 2B?

Answer 24

more agressive

metastatic lesions have been described in infancy