[PATH] Pituitary Pathology Flashcards

1
Q

Histologically, typical pituitary adenomas are composed of what type of cells and how are they arranged?

A

Uniform, polygonal cells arrayed in sheets or cords

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What 2 morphological features of pituitary adenomas distinguish them from non-neoplastic anterior pituitary parenchyma?

A

Cellular monomorphism and absence of a reticulin (CT) network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Atypical adenomas have a higher propensity for aggressive behavior and are associated with mutations in which gene?

A

TP53

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which genetic mutation is seen in many pituitary adenomas, especially somatotroph cell adenomas; leads to what signaling effects?

A

GNAS mutations —> α subunit of Gs loses GTPase activity—> ↑↑↑ cAMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Peak age(s) of incidence for pituitary adenomas?

A

35 to 60 years of age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sometimes rapid enlargement of a pituitary adenoma can lead to acute hemorrhage into an adenoma, a situation known as what?

A

Pituitary apoplexy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Some pituitary adenomas can secrete 2 hormones, what is the most common combination?

A

GH and prolactin = Bihormonal mammosomatotroph adenoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Large pituitary adenomas, particularly nonfunctioning ones, may cause hypopituitarism how?

A

By encroaching on and destroying adjacent anterior pituitary parenchyma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the most common type of lactotroph adenoma based on morphology and what is the major type of cell/characteristics?

A
  • Sparsely granulated lactotroph adenoma
  • Comprised of chromophobic cells w/ juxtanuclear localization of the TF PIT-1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lactotroph adenomas have a propensity to undergo what type of morphological change?

A

Dystrophic calcification, ranging from psammoma bodies to a “pituitary stone.”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Serum concentrations of what tend to correlate with the size of a lactotroph adenoma?

A

Prolactin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the most common presenting sx’s of lactotroph adenoma in women?

A
  • Amenorrhea
  • Galactorrhea
  • Diminished libido
  • Infertility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the most common presenting sx’s of lactotroph adenoma in men?

A
  • Decreased libido
  • Decreased sperm count
  • Mass effect** –> Macroadenomas more common
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is another cause of pathologic hyperprolactinemia in the absence of a lactotroph adenoma?

A

Lactotroph hyperplasia due to loss of dopamine-mediated inhibition of prolactin secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Hyperprolactinemia in the absence of an adenoma may also be due to what other disease states?

A

Renal failure or hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Lactotroph adenomas can be treated with what drugs?

A

Dopamine agonists - Bromocriptine or Cabergoline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which 2 serum markers are indicative of a GH-secreting somatotroph adenoma?

A

↑↑↑↑ GH and IGF-1 levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is one of the most sensitive tests for acromegaly?

A

Failure to suppress GH production in response to an oral glucose load

19
Q

What are 2 pharmacological tx options for GH-secreting somatotroph adenomas?

A

Somatostatin analogs or GH receptor antagonists

20
Q

Majority of corticotroph adenomas are what size at the time of diagnosis?

A

Microadenomas

21
Q

What is the most commonly seen morphology of corticotroph adenomas?

A

Basophilic (densely granulated) and occassionally chromophobic (sparsely granulated)

22
Q

Corticotroph adenomas stain positively with what stain due to the presence of POMC?

A

PAS

23
Q

Explain the mechanism underlying the development of a large destructive pituitary adenoma aka Nelson Syndrome.

A

Develops folllowing surgical removal of adrenal glands for tx of Cushing Syndrome due to loss of the inhibitory effect of adrenal corticosteroids on a preexisting coritcotroph adenoma

24
Q

How do patients with Nelson Syndrome most commonly present?

A

With mass effect (i.e., HA’s or bitemporal hemianopia) due to the pituitary tumor and hyperpigmentation due to stimulatory effect of POMC on melanocytes

25
Q

What changes to the skin may be seen with Hypercortisolism?

A

Thinning of skin and striae

26
Q

What are the 3 major types of cancer associated with paraneoplastic secretion of ACTH or ACTH-like substance leading to Cushing Syndrome?

A
  • Small-cell carcinoma of lung
  • Pancreatic carcinoma
  • Neural tumors
27
Q

How can the high-dose dexamethasone suppression test help to distinguish corticotroph adenomas from ACTH-secreting tumors?

A

Corticotroph adenomas will show suppression of ACTH on high-dose dexamethasone suppression test

28
Q

How will corticotroph adenomas respond to CRH stimulation test vs. ACTH-secreting tumors?

A

Corticotroph adenomas will have ↑↑↑ response to CRH stimulation test

29
Q

Pharmacologic tx of corticotroph adenomas?

A

Somatostatin analogs or bromocriptine since some express dopamine receptors and somatostatin receptors

30
Q

The presence of what are essential conditions for the presence of a pituitary carcinoma?

A

Presence of craniospinal or systemic metastases

31
Q

Pituitary apoplexy in its most dramatic presentation produces sudden onset of what sx’s?

A
  • Excruciating HA
  • Diplopia
  • Hypopituitarism
32
Q

Which mutation is associated with familial pituitary adenomas, known as pituitary adenoma predisposition (PAP) syndrome?

A

Loss-of-function of AIP

33
Q

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

A

Sheehan syndrome aka postpartum necrosis

34
Q

List some conditions which may be associated with pituitary necrosis

A
  • DIC
  • Sickle cell anemia
  • ↑ ICP
  • Traumatic injury
  • Shock
35
Q

What are Rathke cleft cysts lined with and how can they lead to hypopituitarism?

A
  • Ciliated cuboidal epithelium w/ occasional goblet cells and anterior pituitary cells
  • Can accumulate proteinaceous fluid and expand
36
Q

What occurs in primary empty sella syndrome?

A

Defect in diaphragma sella causes arachnoid mater + CSF to herniate into the sella, expanding the sella and compressing the pituitary

37
Q

Primary empty sella syndrome is most commonly seen in whom?

A

Obese women w/ a hx of multiple pregnancies

38
Q

How do individuals with primary empty sella syndrome commonly present?

A

Visual field defects and occasional endocrine abnormalities such as hyperprolactinemia

39
Q

What occurs in secondary empty sella syndrome?

A

Pituitary adenoma enlarges the sella and is then either surgically removed or undergoes infarction –> loss of pituitary function + empty space

40
Q

What is an example of an inflammatory disorder and infection which can involve the hypothalamus and cause deficiencies of anterior pituitary hormones and diabetes insipidus?

A
  • Sarcoidosis
  • Tuberculous meningitis
41
Q

Craniopharyngiomas may be seen in which 2 age groups; what is the most common type and dysfunction caused in each?

A
  • Kids (5-15 y/o) = adamantinomatous craniophryngiomas; growth retardation from hypopituitarism
  • Adults (>65 y/o) = papillary craniopharyngiomas; signs of ↑ ICP or hypopituitarism
42
Q

What are 4 histological findings of adamantinomatous craniopharyngiomas?

A
  • Squamous epithelium embedded in spongy “reticulum” w/ “palisading” at the periphery
  • “Wet” keratin
  • Calcified cyst aka dystrophic calcification
  • Cholesterol-rich, thick brownish yellow fluid (“machine oil”)
43
Q

Cerebral edema w/ resultant neuro dysfunction is associated with what disorder of ADH?

A

SIADH

44
Q

What do the papillary type of craniopharyngiomas lack histologically?

A

Usually lack keratin, calcification, and cysts