Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Endocrine System > Pituitary Pathology > Flashcards

Pituitary Pathology Flashcards

1
Q

What do the pink acidophils of the pituitary gland secrete?

A

Growth hormone and prolactin

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

What do the dark purple basophils secrete?

A

Corticotropin (ACTH)
TSH
Gonadotrophins (FSH and LH)

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

What hormones does the adenohypophysis secrete?

A

Six hormones:
1. ACTH
2. FSH
3. GH
4. LH
5. PRL
6. TSH

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

What are the stimulatory releasing factors that the anterior pituitary hormones are under control of?

A

Corticotropin-releasing hormone (CRH)
GHRH
Gonadotropin-releasing hormone (GnRH)
TRH

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

What are the inhibitory releasing factors that the anterior pituitary hormones are under control of?

A

Growth inhibitory hormone (Somatostatin)
Prolactin inhibitory factor (Dopamine)

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

What is the population of pituitary adenomas?

A

ADults 35 to 60 years of age

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

How are pituitary adenomas classified?

A

Based on hormone production (Functional & Non-functional)

According to size

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

What are micro adenomas?

A

Less than 1 cm

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

What are macro-adenomas?

A

More than 1cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the pathogenesis of sporadic pituitary adenoma?

A
  1. Activating mutation in the GNAS (G protein mutation) –> that interferes with its intrinsic GTPase activity
  2. Constitutive activation of Gs(a) and adenylate cyclase, persistent generation of cAMP (potent mitogen)
  3. Stimulate hypersecretion and cell proliferation (mainly GH adenoma)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the % of familial pituitary adenoma?

A

5%

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

What are the different types of familial pituitary adenomas?

A
  1. Multiple Endocrine Neoplasia Type 1 (MEN-1)
  2. Carney Complex Syndrome
  3. Familial Isolated Adenomas (FIPAs)
  4. Mutations of Cyclin-Dependent Kinase Inhibitor 1B
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the Carney Complex Syndrome?

A

Mutation in the gene for protein kinase A regulatory subunit I a (PRKAR1A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does Carney Complex Syndrome result in?

A

Acromegaly (GH & prolactin secretion)

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

What are familial isolated adenomas?

A

Mutation in aryl hydrocarbon receptor-interacting gene (AIP)

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

What is the result of familial isolated adenomas?

A

Develop GH-secreting adenomas at a younger age (before the age of 35)

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

WHat are mutations of cyclin-dependent kinase inhibitor 1B?

A

CDKN1B gene is the cell cycle checkpoint regulator p27 or KIP1 –> aggressive adenoma (Cyclin D1, TP53, RB)

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

What is the gross anatomy of small lesion pituitary adenomas?

A

Well-circumscribed, soft lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the gross anatomy of large lesion pituitary adenomas?

A
  1. They compress the optic chiasm and adjacent structures (extend locally into the cavernous and sphenoidal sinuses)
  2. Foci of hemorrhage and/or necrosis are common in larger adenomas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the microscopic features of pituitary adenomas?

A
  1. Cellular monomorphism of one cell type
  2. Absence of a significant reticulin network
  3. Hemorrhage and necrosis may occur
  4. Rare mitosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the growth pattern of the pituitary adenomas?

A

Diffuse trabecular, pseudo-acinar or psedo-papillary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is used for hormonal identification of pituitary adenomas (microscopically)?

A

Immunohistochemistry (IHC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the symptoms of the pituitary adenomas?

A

Local mass effects
Hyperpituitarism
Hypopituitarism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the radiographic abnormalities of the sella turcica in the local effects of pituitary adenomas?

A

Sellar expansion
Bony erosion
Disruption of the diaphragma sellae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the mass effects of pituitary adenomas?

A

Local effects
Compress decussating fibers in the optic chiasm
Elevated intracranial pressure
Invasive pituitary adenoma
Acute hemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the effect of compressing decussating fibers in the optic chiasm?

A

Bitemporal hemianopsia (defects in the lateral visual fields –> tunnel)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the effects of elevated intracranial pressure?

A

Expanding intracranial mass:
1. Headache
2. Nausea and vomiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the effects of invasive pituitary adenomas?

A

They extend beyond the sella turcica:
1. Seizures
2. Obstructive hydrocephalus
3. Cranial nerve palsy (involvement of cranial nerves)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the effect of acute hemorrhage (pituitary apoplexy)?

A

Rapid enlargement of the lesion –> loss of consciousness –> sudden death (neurological emergency)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is hypepituitraism?

A

Excessive secretion of trophic hormones (FSH, LH, ACTH, TSH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the causes of hyperpituitarism?

A

Anterior pituitary adenoma (most common)
Pituitary hyperplasia (less common)
Pituitary carcinoma and hypothalamic causes (even less common)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the effect of pituitary hyperplasia?

A

Secretion of hormones by extra pituitary site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the types of functioning adenomas pituitary cell types?

A
  1. Corticotroph
  2. Somatotroph
  3. Lactotroph
  4. Mammosomatotroph
  5. Thyrotroph
  6. Gonadotroph
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the hormones associated with corticotrophin?

A

ACTH and other POMC-derives peptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the type of tumor associated with corticotrophs?

A

ACTH cell (corticotroph) adenoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the associated syndromes with corticotroph tumors?

A

Cushing’s syndrome
Nelson syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the hormones associated with somatotrophs?

A

GH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the type of tumor associated with somatotrophs?

A

GH cell (somatotroph) adenoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the associated syndromes with somatotroph tumors?

A

Gigantism (children)
Acromegaly (adults)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the hormones associated with lactotrophs?

A

Prolactin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the type of tumor associated with lactotrophs?

A

Prolactin cell (lactotroph) adenoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are the associated syndromes with lactotroph tumors?

A

Galactorrhea and amenorrhea (in females)
Sexual dysfunction, infertility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are the hormones associated with mammosomatotrophs?

A

Prolactin
GH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the type of tumor associated with mammosomatotrophs?

A

Mammosomatotroph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are the associated syndromes with mammosomatotroph tumors?

A

Combined features of GH and Prolactin excess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are the hormones associated with thyrotrophs?

A

TSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the type of tumor associated with thyrotrophs?

A

TSH cell (thyrotroph) adenoma

48
Q

What are the associated syndromes with thyrotroph tumors?

A

Hyperthyroidism

49
Q

What are the hormones associated with gonadotrophs?

A

FSH
LH

50
Q

What is the type of tumor associated with gonadotrophs?

A

Gonadotroph, “null cell” oncocytic adenomas

51
Q

What are the associated syndromes with gonadotroph tumors?

A

Hypogonadism, mass effects, and hypopituitarism

52
Q

What is a prolactinoma?

A

The most common type of pituitary adenoma, it is a tumor of lactotroph cells

53
Q

Who is more likely to get affected by prolactinomas?

A

Females > Males
Age 20 to 50

54
Q

What are the effects of female prolactinoma microadenoma? (< 10mm)

A

Galactorrhea
Amenorrhea
Infertility

55
Q

What are the effects of male prolactinoma macroadenoma (>10mm)?

A

Decreased libido,
Gynecomastia,
Infertility

56
Q

What is the male and female mass effects of prolactinomas?

A

Headaches,
CSF rhinorrhea,
Compression of optic chiasma & optic nerve

57
Q

What are the functions of prolactin?

A
  1. Stimulates milk production in breast
  2. Inhibits ovulation in females and spermatogenesis in males by inhibiting GnRH synthesis and release
  3. Excessive amount associated with decreased libido
58
Q

What inhibits prolactin?

A

Dopamine
Dopamine agonists

59
Q

What does prolactin inhibit?

A

Its own secretion by dopamine synthesis and secretion from hypothalamus

60
Q

Which hormone affects prolactin secretion positively?

A

TRH (primary or secondary hypothyroidism for example)

61
Q

What is an example of a dopamine agonist?

A

Bromocriptine

62
Q

What substances stimulate prolactin secretion?

A

Dopamine antagonists
Estrogens

63
Q

What are examples of dopamine antagonists?

A

Antipsychotics

64
Q

What are examples of estrogens?

A

Oral contraceptives
Pregnancy

65
Q

What is the diagnosis of prolactinoma?

A

Serum prolactin level > 200mcg/L
Radiology CT or MRI

66
Q

What are other causes that could have led to an increase in serum prolactin levels?

A
  1. Renal failure
  2. High dose estrogen
  3. Pregnancy
  4. Hypothyroidism
  5. Hypothalamic lesions
  6. Dopamine inhibiting drugs
67
Q

How does renal failure increase prolactin levels?

A

Urea toxic effects on hypothalamus –> decrease in dopamine, which inhibits the secretion of prolactin

68
Q

What is the treatment for prolactinomas?

A

Medical: dopamine agonist (to suppress prolactin and shrink tumor)
Surgical: in the case that medical treatment fails, sometimes followed by RT

69
Q

What are the microscopical findings of prolactinomas?

A
  1. Chromophobic in staining (sparsely granulated) & acidophilic (densely granulated)
  2. Spheroid nuclei
  3. Prominent nucleolus
  4. Sometimes, endocrine amyloid
  5. Psammoma bodies
70
Q

What are growth hormone adenomas?

A

2nd most common
Tumour of somatotroph cells

71
Q

What may adenomas produce?

A

A mixture of growth hormone and other hormones (like prolactin for instance)

72
Q

What are the mutations of growth hormone adenomas?

A

40% have activated GNAS gene on chromosome 20q13 –> G protein –> continue cAMP production & cell proliferation

73
Q

What is the result of persistent growth hormone?

A

Stimulates the hepatic secretion of insulin-like growth factor 1, which acts in conjunction with growth hormone to induce overgrowth of bone and muscles

74
Q

What are the clinical features of growth hormone adenoma?

A

Gigantism in children
Acromegaly in adults

75
Q

What is gigantism?

A

Generalized increase in body size, with dispospprtioately long arms and legs

76
Q

What is acromegaly? (5)

A
  1. Growth in soft tissues, skin, and viscera and in the bones of the face, hands, and feet
  2. Enlarged jaw with broadening of the lower face and enlarged tongue and teeth separation
  3. Hands and feet are enlarged, with broad, sausage-like fingers
  4. Secondary DM
  5. Muscle weakness, HTN, arthritis, osteoporosis, and Biventricular hypertrophy
77
Q

What tumors’ risk increases with Acromegaly?

A

GIT tumours

78
Q

What are the diagnostic criteria for Growth hormone adenoma? (4)

A
  1. Increase in growth levels
  2. Increase in IGF-1
  3. Lack of GH suppression by oral glucose
  4. Radiology CT or MRI
79
Q

What are the treatment methods for growth hormone adenomas?

A

Somatostatin (suppressed GH)
Surgery

80
Q

what are the microscopical findings of growth hormone adenoma?

A

Densely granulated form composed of acidophilic cells

Sparsely granulated variety that features chromophobic cells

81
Q

What are adenocorticotrophic hormone-producing adenomas?

A

they secrete ACTH, leading to Cushing’s disease
Associated with hyperpigmentation (increase in MSH, derived from the same precursor as ACTH)

82
Q

What are adenocorticotrophic hormone-producing adenomas like at the point of diagnosis?

A

Microadenomas

83
Q

How do adenocorticotrophic hormone-producing adenomas stain?

A

Stain positively with periodic acid-Schiff stains because of the accumulation of glycosylated ACTH protein)

Secretory granules can be detected by IHC methods

84
Q

What are non-functioning adenomas?

A

Null cell adenomas, usually macroadenomas, later presentation as no hormones

Hypopituitarism as it destroys adjacent pituitary parenchyma

85
Q

What do non-functioning adenomas present by usually?

A

Mass Effect

86
Q

What is hypopituitarism?

A

Insufficient hormone production by the anterior pituitary,
It can be a deficiency in one hormone, several hormones, or complete pituitary failure

87
Q

When do symptoms of hypopituitarism arise?

A

When > 75% of pituitary parenchyma is lost

88
Q

What are the causes of hypopituitarism?

A
  1. Mass Effect by a pituitary tumor in adults and craniopharyngioma in children
  2. Bleeding in pituitary tumour
  3. Ischemic necrosis as Sheehan syndrome, or DIC, increase in IPC, trauma/shock and SCA
  4. Ablation of the pituitary gland by surgery or irradiation
  5. Empty sella syndrome
  6. Inflammatory lesions
  7. Metastatic tumours
  8. Hypothalamic tumors
  9. Growth hormone insensitivity
  10. Hemochromatosis
89
Q

What is Sheehan syndrome?

A

Pregnancy-related infraction (gland size enlarged in pregnancy but blood supply does not, blood loss during childbirth) –> present poor lactation, loss of pubic hair, fatigue, and other features

90
Q

What is empty sella syndrome?

A

Congenital or acquired by herniation of arachnoid & CSF into sella compresses and destroys the pituitary gland, especially in obese women

91
Q

What is an example of growth hormones insensitivity?

A

Laron Dwarfism –> AR due to abnormality of GH receptor

92
Q

What are the clinical features of hypopituitarism? (GH deficiency in children)

A

Growth failure (pituitary dwarfism)

93
Q

What are the clinical features of hypopituitarism? (Gonadotrophin or GnRH deficiency)

A

Female: amenorrhea and infertility
Male: decreased libido, impotence, and loss of pubic and axillary hair

94
Q

What are the clinical features of hypopituitarism? (TSH and ACTH deficiencies)

A

Hypothyroidism and hypoadrenalism

95
Q

What are the clinical features of hypopituitarism? (Prolactin deficiency)

A

Failure of postpartum lactation

96
Q

What are the clinical features of hypopituitarism? (Loss of stimulatory effects of MSH on melanocytes)

A

Pallor

97
Q

What are the hormones of the posterior pituitary gland?

A

ADH and Oxytocin

98
Q

Where does ADH function?

A

Acts on the kidney distal tubule and collecting ducts and promotes retention of water

99
Q

Where does oxytocin fucntion?

A

Mediates uterine contractions during labor and milk release in lactating mothers

100
Q

What are the stimulating factors of ADH?

A

Plasma oncotic pressure
Exercise
Decrease in blood volume
Emotional state

101
Q

How does a decrease in blood volume increase ADH stimulation?

A

Decrease in blood volume –> filling of atria –> stretch receptors not stimulated –> no inhibitory signal to the brain –> increase ADH secretion

102
Q

What is diabetes insipidus?

A

ADH deficiency (central or cranial DI) or impaired renal response to ADH (nephrogenic ADH)

103
Q

What are the characteristics of diabetes insipidus?

A

Inability to concentrate urine and consequent chronic water diuresis

104
Q

What are the clinical features of diabetes insipidus? (6)

A

Due to loss of free water:
1. Polyuria
2. Thirst
3. Polydypsia & dehydration
4. postural hypotension
5. Increased serum osmolality and hypernatremia
6. Urien is diluted with low sepcific gravity

105
Q

What are the causes of central DI? (7)

A
  1. Idiopathic
  2. Brain tumours
  3. Head injuries
  4. Brain malformation
  5. Infections (meningitis, encephalitis, TB)
  6. Surgery
  7. Radiotherapy
106
Q

What are the causes of nephrogenic DI? (4)

A
  1. Drugs (lithium)
  2. Genetic (AVPR2 gene)
  3. Intrinsic Kidney Disease
  4. Electrolytes (hypokalemia, hypercalcemia)
107
Q

What are the diagnostic criteria for DI?

A

Increased serum osmolality and Na
Decreased urine osmolality and low specific gravity

108
Q

What is the syndrome of inappropriate ADH secretion (SIADH) ?

A

Excess ADH secretion

109
Q

What are the effects fo SIADH?

A
  1. Retention of water –> hyponatremia and low serum osmolality
  2. Hyponatremia –> neuronal swelling and cerebral edema –> mental hanges and seizures
110
Q

What is the blood volume like in SIADH?

A

Normal blood volume and no peripheral edema

111
Q

What are the causes of SIADH? (4)

A
  1. Ectopic production (Lung small cell carcinoma)
  2. CNS trauma, stroke, infection, and tumors
  3. Pulmonary infections & COPD
  4. Drugs (cyclophosphamide, antipsychotic, NSAIDs)
112
Q
A
113
Q
A
114
Q
A
115
Q
A
116
Q
A
117
Q
A

Endocrine System (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions