Pathology of the Pituitary and Adrenal Glands Flashcards
(82 cards)
1
Q
By which other name is the anterior pituitary known?
A
Adenohypophysis
2
Q
What is the anterior pituitary dervived from?
A
Rathke’s pouch
3
Q
Which 2 types of hormones does the anterior pituitary secrete?
A
- Trophic
- Non-trophic
4
Q
What is a trophic hormone?
A
A hormone which stimulates the activity of another endocrine gland
5
Q
By which other name is the posterior pituitary known?
A
Neurohypophysis
6
Q
What does the posterior pituitary mostly consist of?
A
Extension of neural tissue:
- Modified glial cells
- Axonal processes
7
Q
Which 3 cell types are found in the anterior pituitary?
A
- Acidophils
- Basophils
- Chromophobes
8
Q
What are the two types of acidophils found in the anterior pituitary and which hormones do they each secrete?
A
- Somatotrophs - GH
- Mammotrophs - PRL
9
Q
What are the 3 types of basophils found in the anterior pituitary and which hormones does each secrete?
A
- Corticotrophs - ACTH
- Thyrotrophs - TSH
- Gonadotrophs - FSH/LH
10
Q
What may be the cause of anterior pituitary hyperfunction?
A
Adenoma/carcinoma
11
Q
What may be the cause of anterior pituitary hypofunction?
A
- Surgery/radiation
- Sudden gland haemorrhage
- Ischaemic necrosis
- Tumours extending into the sella
- Inflammatory conditions such as sarcoidosis
12
Q
What is Sheenhan syndorme?
A
Hypopituitarism due to ischemic necrosis as a result of blood loss and hypovolemic shock associated with childbirth.
(it is also known as postpartum pituitary gland necrosis)
13
Q
What is SIADH?
A
Syndrome of inappropriate ADH secretion
14
Q
SIADH may have which two underlying causes?
A
- Ectopic secretion of ADH (tumours)
- Primary pituitary disorder
15
Q
How can pituitary adenomas be classified?
A
- Cell type affected
- Hormone produced (or not produced in some cases)
16
Q
A pituitary adenoma may be sporadic or associated with which condition?
A
MEN1
17
Q
What are the major problems associated with large pituitary adenomas?
A
- Visual field defects
- Pressure atrophy of surrounding tissue
- Infarction leading to panhypopituitarism
18
Q
What is the most common functional pituitary adenoma?
A
Prolactinoma
19
Q
What is the second most functional pituitary adenoma?
A
GH secreting adenoma
20
Q
GH secreting adenomas can cause which two things based on the age and development of the affceted individual?
A
- Giantism
- Acromegaly
21
Q
An ACTH secreting pituitary adenoma can cause Cushing’s disease, what is another major cause of the condition?
A
Bilateral adrenocortical hyperplasia
22
Q
Pituitary hypofunction rarely affects just one hormone, it affects many. This is called what?
A
Pan hypopituitarism
23
Q
Pituitary hypofunction (or pan hypoituitarism) can be caused by which three things?
A
- Granulomatous inflammation (e.g. sarcoidosis)
- Infarction (e.g. Sheehan’s syndrome)
- Primary or metastatic tumours
24
Q
What is the name given to the brain tumour derived from Rathke’s pouch?
A
Craniopharyngioma
25
What may be a key diagnostic sign on a scan for a craniopharyngioma?
Presence of **calcification**
26
What are the key clinical signs of a craniopharyngioma?
1. Visual disturbances
2. Growth retardation in children
27
Following radiation for a craniopharyngioma, what may subsequently develop?
Squamous cell carcinoma (SCC)
| (this is rare)
28
For which three reasons may diabetes insipidus develop?
1. Centrally - **Deficient** ADH production
2. Peripherally - Renal **resistance** to ADH effects
3. SIADH - **Ectopic** ADH release
29
Each adrenal gland is composed of an outer ________ and an inner \_\_\_\_\_\_\_\_\_\_
Each adrenal gland is composed of an outer **cortex** and an inner **medulla**
30
Waterhouse-Friderichsen syndrome is caused by ________ adrenal \_\_\_\_\_\_\_\_\_\_\_\_\_
Waterhouse-Friderichsen syndrome is caused by **acute** adrenal **hypofunction**
31
What causes Waterhouse-Friderichsen syndrome?
**Adrenal gland failure** due to bleeding into the adrenal glands
Commonly caused by severe bacterial infection, typically
**Neisseria meningitidis**
32
Addison's disease is caused by ________ adrenal \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Addison's disease is caused by **chronic** adrenal **hypofunction**
33
What is congenital adrenal hyperplasia?
A group of autosomal recessive conditions
Results from mutations in different genes for enzymes which mediate the **conversion of cholesterol** to mineralocorticoids, glucocorticoids and sex steroids
34
Why does congenital adrenal hyperplasia result in adrenal hyperplasia?
Generally in CAH there is **poor cortisol production**
Low cortisol levels result in **high ACTH** levels (an attempt to upregulate cortisol)
High ACTH acts on steroid producing cells in the adrenal cortex causing **hyperplasia and overactivity**
35
What are the clinical features of CAH assoicated with 21-hydroxylase deficiency?
1. Virilisation of female genitalia
2. Precocious puberty in males
3. 60-70% of patients have a salt-losing crisis at 1-3 wks of age
36
What are the clinical features of CAH assoicated with 11-beta hydroxylase deficiency?
1. Virilisation of female genitalia
2. Precocious puberty in males
3. Hypertension
4. Hypokalaemia
37
What are the clinical features of CAH assoicated with 17-hydroxylase deficiency?
1. Non-virilising in females
2. Inter-sex in boys
3. Hypertension
38
Acquired adrenocortical hyperplasia can be brought about in which ways?
Endogenous ACTH production
1. Pituitary adenoma (Cushing’s disease)
2. Ectopic ACTH (e.g. small cell lung cancer)
39
Adrenocortical adenomas are usually functional
True or false?
False
40
It can be very difficult to differentiate between adrenalcortical adenomas and adrenocortical carcinomas. In which ways may an adrenalcortical carcinoma be suspected?
1. Large size (\>50g, often \>20cm)
2. Haemorrhage and necrosis
3. Frequent mitoses, atypical mitoses
4. Lack of clear cells
5. Capsular or vascular invasion
41
What is the name given to primary hyperaldosteronism?
Conn's syndrome
42
Which two things is Conn's syndrome most commonly associated with?
1. Adrenal adenoma
2. Diffuse or nodular hyperplasia of both adrenal glands
43
Conn's syndrome is responsible for causing \_\_\_\_\_\_\_\_\_\_\_\_
Conn's syndrome is responsible for causing **hypertension**
44
A triad of which three things should cause suspicion of Conn's syndrome?
1. Hypokalaemia
2. Hypertension
3. Alkalosis
45
The clinical picture of Conn's syndrome is similar to which other condition, yet how can the two be differentiated?
Renal artery stenosis
1. Conn's - low plasma renin
2. Renal artery stenosis - high plasma renin
46
Hypercortisolism is also known by which other name?
Cushing's disease or syndrome
47
Cushing's can be caused by either ___________ or ____________ causes
Cushing's can be caused by either **endogenous** or **exogenous** causes
48
What is the exogenous cause for Cushing's syndrome?
Steroid therapy overdose
49
Endogenous Cushing's disease can be either ________ dependedent or independent
Endogenous Cushing's disease can be either **ACTH** dependedent or independent
50
What does any cause of ACTH dependent Cushing's disease lead to?
Adrenal hyperplasia
51
What are the two main causes of ACTH dependent Cushing's?
1. ACTH secreting pituitary adenoma (70%)
2. Ectopic ACTH release (e.g. small cell lung cancer) (10%)
52
ACTH independent Cushing's is most likely caused by what?
1. Adrenal adenoma
2. Adrenal carcinoma
53
How does ACTH independent Cushing's affect the adrenal glands?
Non-lesional adrenal gland atrophies
54
Adrenocortical hypofunction can have _________ or __________ causes
Adrenocortical hypofunction can have **primary** or **secondary** causes
55
Secondary adrenocortical hypofunction usually results mainly from which two things?
1. Failure to stimulate adrenal cortex (e.g. hypopituitarism)
2. Suppression of adrenal cortex (e.g. treatment with steroids)
56
Acute primary adrenocortical insufficiency can be induced when which type of medication is rapidly withdrawn?
Steroids
57
Acute primary adrenocortical insufficiency can also be brought about by massive adrenal haemorrhage. What may cause this?
1. Newborn (adrenal glands are much larger in relative size and very vascular)
2. Anticoagulant treatment
3. Disseminated intravascular coagulation
4. Septicaemic infection (leads to Waterhouse-Friderichsen syndrome)
58
Chronic adrenocortical insufficiency is also know by which other name?
Addison's disease
59
What are the four commonest causes of Addison's disease?
1. Autoimmune adrenalitis
2. Infections
3. Metastatic malignancy (lung, breast)
4. Anti-phospholipid syndrome
60
Which types of infections are associated with inducing Addison's disease?
1. TB
2. Fungal
3. HIV
61
Name four more unusual causes of Addison's disease
1. Amyloid deposition
2. Sarcoidosis
3. Haemochromatosis
62
Signs and symptoms of Addison's disease develop after how much of the adrenal gland has been destroyed?
\>90%
63
What are the symptoms of Addison's disease?
1. Weakness and fatigue
2. Vomiting and weight loss
3. Diarrhoea
4. Pigmentation of the skin and mucosal membranes
64
Addison's diease is associated with hypo\_\_\_\_\_\_\_ and hyper\_\_\_\_\_\_\_\_
Addison's diease is associated with hypo**natraemia** and hyper**kalaemia**
(K+ retention, Na+ loss)
65
In a patient with Addison's disease, what is the expected blood pressure and why?
Low
Volume depletion
66
Which mineralocorticoid is decreased in Addison's disease?
Aldosterone
67
A reduced aldosterone level contributes to which characteristic traits of Addison's disease?
1. Hyperkalaemia (failure to secrete)
2. Hyponatraemia (failure to retain)
3. Hypotension (water follows Na+; failure to retain)
68
In Addison's disease there is __________ glucocorticoids, what is the effect of this?
**Decreased** glucocorticoids (cortisol)
Cortisol usually acts on the liver to induce gluconeogenesis
In Addison's disease, this system fails and **hypoglycaemia** occurs
69
What is an Addisonian crisis?
A range of symptoms suggesting severe adrenal insufficiency.
This is a **medical emergency**
1. Hypovolaemic shock
2. Hyponatraemia
3. Hyperkalaemia
4. Hypercalcaemia
5. Fever
6. Abdominal pain and vomiting
7. Convulsions
8. Coma and death
70
Neuroendocrine (chromaffin) cells are located where and secrete what?
Adrenal medulla
Catechloamines
(epinephrine, norepinephrine, and dopamine)
71
Which tumour can appear in the adrenal medulla and is composed of primative looking cells which indicate differentiation towards ganglion cells?
Neuroblastoma
72
A neuroblastoma is usually diagnosed by which age?
18 months
73
What is the name given to a tumour derived from chromaffin cells of the adrenal medulla?
Phaechromocytoma
74
Why is a phaechromocytoma is cause of secondary hypertension?
Secretion of catechloamines raised blood pressure by activating the sympathetic nervous system
75
What are the key cardiovascular complications of phaeochromocytoma?
1. Cardiac failure
2. Infarction
3. Arrhythmias
4. Stroke
76
How can a phaeochromocytoma be diagnosed?
Urinary secretion of catechloamines and metabolities
77
10% of phaeochromocytomas are \_\_\_\_\_\_\_-adrenal and 10% are \_\_\_\_\_\_\_\_\_\_
10% of phaeochromocytomas are **extra**-adrenal and 10% are **bilateral**
78
Phaeochromocytomas can be associated with genetics
True or false?
True
Up to 25% are familial
79
What is the term given to the small nests that phaeochromocytoma tumour cells create?
Zellballen
80
Phaeochromocytomas have a propensity for metastases to which location?
Skeletal
(they can also metastasise to regional lymph nodes, liver and lung)
81
What is Sipple syndrome?
Multiple endocrine neoplasia type 2A (MEN2A)
82
Phaeochromocytoma is a feature of which type of MEN?
MEN2A and MEN2B
