patho case 1 (1074-1082)

Question 1

what transcription factor is needed for somatotrophs, mammosomatotrophs, and lactotrophs

Answer 1

PIT-1

Question 2

what transcription factors are needed for gonadotroph differentiation

Answer 2

SF-1 and GATA-2

Question 3

what does hyperpituitarism arise from

Answer 3

excess secretion of trophic hormones

Question 4

what does hypopituitarism arise from

Answer 4

deficiency of trophic hormones

Question 5

what is the most common cause of hyperpituitarism

Answer 5

adenoma arising in the anterior lobe

Question 6

describe functional adenomas

Answer 6

associated with hormone excess and clinical manifestations thereof

Question 7

describe nonfunctioning adenomas

Answer 7

without clinical symptoms of hormone excess

Question 8

how big are micro adenomas

Answer 8

less than 1 cm in diameter

Question 9

what are the associated syndrome with lactotroph adenomas

Answer 9

galactorrhea and amenorrhea, sexual dysfunction, infertility

Question 10

what are the associated syndrome with somatotroph adenomas

Answer 10

gigantism and acromegaly

Question 11

what is the most commonly associated pituitary tumor with gain of function GNAS

Answer 11

GH adenoma

Question 12

what is the most commonly associated pituitary tumor with gain of function PRKAR1A

Answer 12

GH and prolactin adenomas

Question 13

what is the most commonly associated pituitary tumor with gain of function cyclin D1

Answer 13

aggressive adenomas

Question 14

what is the most commonly associated pituitary tumor with gain of function HRAS

Answer 14

pituitary carcinomas

Question 15

what is the most commonly associated pituitary tumor with loss of function MEN1

Answer 15

GH, prolactin, and ACTH adenomas

Question 16

what is the most commonly associated pituitary tumor with loss of function CDKN1B

Answer 16

ACTH adenomas

Question 17

what is the most commonly associated pituitary tumor with loss of function AIP

Answer 17

GH adenomas

Question 18

xwhat is the most commonly associated pituitary tumor with loss of function RB

Answer 18

aggressive adenomas

Question 19

what is the mechanism of alteration with GNAS

Answer 19

activating mutation

Question 20

what is the mechanism of alteration with PRKAR1A gain of function

Answer 20

gremlin inactivating mutations of PRKAR1A are present in autosomal dominant carney complex

Question 21

what is the mechanism of alteration with cyclin D1 gain of function

Answer 21

overexpression

Question 22

what is the mechanism of alteration with HRAS gain of function

Answer 22

activating mutation

Question 23

what is the alpha-subunit of Gs encoded by

Answer 23

GNAS gene

Question 24

what chromosome is the GNAS gene on

Answer 24

20q13

Question 25

describe the typical pituitary adenoma

Answer 25

soft and well-circumscribed

Question 26

what distinguishes pituitary adenomas from nonneoplastic anterior pituitary parenchyma

Answer 26

cellular monomorphism and the absence of a significant reticulin network

Question 27

what is the most frequent type of hyper functioning pituitary adenoma

Answer 27

prolactin-secreting lactotroph adenomas

Question 28

what adenomas are lactotroph adenomas comprised of chromophoric cells with juxtanuclear localization of PIT-1

Answer 28

sparsely granulated lactotroph adenomas

Question 29

what adenomas are characterized by diffuse cytoplasmic PIT-1 expression localization

Answer 29

densely granulated lactotroph adenomas

Question 30

what does prolactinemia cause

Answer 30

amenorrhea, galactorrhea, loss of libido, and infertility

Question 31

what is lactotroph hyperplasia caused by

Answer 31

loss of dopamine-mediated inhibition of prolactin secretion

Question 32

what is densely granulated adenomas composed of

Answer 32

monomorphic, acidophilic cells that have strong cytoplasmic GH reactivity on immunohistochemistry

Question 33

what are sparsely granulated variants composed of

Answer 33

chromophobe cells with considerable nuclear and cytoplasmic pleomorphism and focal, weak staining for GH

Question 34

describe corticotroph adenomas

Answer 34

usually micro adenomas at the time of diagnosis and are most often basophilic (densely granulated) and occasionally chromophoric (sparsely granulated)

Question 35

why does nelson syndrome occur most often due to

Answer 35

because of a loss of the inhibitory effect of adrenal corticosteroids on a preexisting corticotrophin micro adenoma

Question 36

what is the most common form of clinically significant ischemic necrosis of the anterior pituitary

Answer 36

sheehan syndrome/ postpartum necrosis

Question 37

what are rathe cleft cysts lined by

Answer 37

ciliated cuboidal epithelium with occasional goblet cells and anterior pituitary cells

Question 38

what causes diabetes insipidus

Answer 38

ADH deficiency

Question 39

what is diabetes insipidus characterized by

Answer 39

excessive urination (polyuria) due to an inability of the kindly to resorb water proper from the urine

Question 40

what is nephrogenic diabetes insipidus a result of

Answer 40

renal tubular unresponsiveness to circulating ADH

Question 41

what is the craniopharyngioma thought to arise from

Answer 41

vestigial remnants of rathke pouch