PITUITARY ADENOMA

Question 1

Define pituitary adenomas:

Answer 1

tumors that derive from one of the 5 types of pituitary hormone producing cells within the anterior lobe of pituitary
>95% are sporadic, <5% are genetic

Question 2

what are the size classifications of pituitary adenomas?

Answer 2

microadenoma: <10 mm (functional)
macroadenoma: > or equal to 10 mm (mass effect)

Question 3

how else are pituitary adenomas classified?

Answer 3

secretory and non-secretory

Question 4

pituitary adenoma epidemiology:

Answer 4

• most commonly dx btwn 30-60 y/o
• > 60% benign, 30% invasive, <1% carcinomas
• cause 60% all cases of hypopituitarism

Question 5

pituitary adenoma pathophys:

Answer 5

growth of adenoma will compress surrounding glandular tissue
most adenomas will arise from a single pituitary cell type

Question 6

what type of adenoma are 60% of all pituitary adenomas?

Answer 6

secretory adenomas

Question 7

lactotroph adenomas

Answer 7

40%, most common
increased prolactin leads to hyperprolactinemia

Question 8

somatotroph adenomas

what do they lead to

Answer 8

also most common
increased growth hormone leads to acromegaly or gigantism

Question 9

corticotroph adenomas

what do they increase and lead to?

Answer 9

increased adrenocorticotropic hormone (ACTH) leading to cushings

Question 10

thyrotroph adenomas

Answer 10

rare
increased TSH leads to 2ndary hyperthyroidism

Question 11

what is the most common type of adenoma that is derived from multiple types of pituitary cells secreting more than 1 hormone?

Answer 11

somatotroph + lactotroph
often atypical and/or malignant forms of adenomas, which transform into aggressive and tx-resistant carcinomas

Question 12

what are 40% of all pituitary adenomas?

Answer 12

non-secretory

Question 13

> 80% of non-secretory cases derive from what type of cells of the pituitary

Answer 13

gonadotroph

Question 14

definition of hypopituitarism:

Answer 14

decreased secretion of one, some, or all anterior pituitary hormones

Question 15

what are the causes of hypopituitarism?

three things

Answer 15

1. most common: adenoma
2. infarct
3. 2ndary sempty sella syndrome (head trauma, infxn, radiation therapy, pituitary surgery, Sheehan syndrome)

Question 16

what is the pathophys of hypopituitarism?

Answer 16

destruction of >75% pituitary tissue resulting in sequential loss of anterior pituitary hormones.
sx depend on deficient hormones

Question 17

what are the most common pituitary hormone deficiencies?

Answer 17

gonadotropins resulting in hypogonadism in both men and women

Question 18

what is the clinical presentation of microadenomas <10?

Answer 18

non secretory is asymptomatic
secretory causes hyperpituitarism
- sx depend on effects that excessive hormone exerts on peripheral target organs
- hyperprolactinemia, acromegaly or gigantism, cushings, 2ndary hyperthyroidism

Question 19

what is the clinical presentation of non-secretory macroadenomas >or equal to 10?

Answer 19

MASS EFFECT SYMPTOMS
1. bitemporal hemianopsia- diminished vision in bilateral temporal fields
2. diplopia from compression of optic chiasma nerve
3. opthalmoplegia- paralysis of CN 3,4,6 (extraocular eye muscles); results from invasion of cavernous sinus
4. headache
5. vomitting w/o nausea
6. AMS
7. pituitary apoplexy- sudden loss of blood supply to pituitary gland, leading to tissue necrosis and loss of fxn d/t sudden hemorrhage into adenoma -> excruciating HA and diplopia

Question 20

what is the clinical presentation of secretory macroadenomas >or equal to 10?

Answer 20

hyperpituitarism
sx depend on hormone-specific effects
other hormones are deficient d/t pituitary tissue destruction
mass effect sx

Question 21

how are most microadenomas diagnosed?

Answer 21

incidentally

Question 22

what is clinical suspicion based on?

Answer 22

sx caused by excessive hormone in addition to mass effect symptoms.
this combo suggests pituitary mass

Question 23

what is the gold standard imaging to confirm sellar masses, size, and location?

Answer 23

contrast MRI
(CT used if MRI contraindicated-> pts w/ pacemaker or metallic implants)

Question 24

What laboratory testing is done?

Answer 24

1. basal prolactin levels to assess prolactinomas
2. insulin-like GF-1 levels to assess somatotroph adenomas
3. 24 hr urine cortisol levels to assess corticotroph adenomas
4. thyrotropin-releasing hormone, TSH, free T3 and T4 levels to assess thyrotroph adenomas

Question 25

pituitary adenoma management:

Answer 25

non-secretory microadenomas: no tx, f/u
secretory regardless of size: rq medical therapy to counteract hormonal effects
macroadenomas regardless of hormone production require surgical or radiation therapy to alleviate compression effects (increased intracranial pressure, visual disturbances, headaches)

Question 26

What is involved in adenoma surgical resection?

Answer 26

transphenoidal adenectomy (removal of adenoma) or complete/partial hypophysectomy (removal of pituitary) is used when medical therapy fails
pituitary irradiation can be used to supplement surgical resection
complications: post-op/post-radiation hypopituitarism -> requires life-long hormone replacement therapy

Question 27

what is a prolactinoma?

Answer 27

functional, usually benign lactotroph cell tumor in the anterior pituitary -> prolactinemia

Question 28

what is the most common type of pituitary tumor (adenoma) that accounts for 30% of all pituitary adenomas?

Answer 28

prolactinoma

Question 29

what can cause prolactinoma?

Answer 29

may occur as part of inherited condition called multiple endocrine neoplasia type 1 (MEN 1)

Question 30

signs and symptoms of prolactinoma?

Answer 30

women: galactorrhea, amenorrhea
men: gynecomastia, erectile dysfunction

Question 31

how is prolactinoma diagnosed?

Answer 31

with increased increased serum prolactin

Question 32

first line prolactinoma treatment?

Answer 32

dopamine agonists- to suppress prolactin secretion
- cabergoline ot bromocriptine

Question 33

memorize hormone slide

Answer 33

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