Pathology of the Pituitary Gland Flashcards Preview

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Flashcards in Pathology of the Pituitary Gland Deck (45):
1

What are the size classifications of pituitary tumours?

less/equal 1cm = microadenoma
>1cm = macroadenoma

2

What 2 structures can a non-functioning pituitary adenoma or a pituitary tumour compress?

Optic chiasma
Cranial Nerves 3,4,6

3

What cells are a pituitary adenoma derived form?

Cells from anterior pituitary

4

How are pituitary adenomas classified?

Cell type or hormone produced

5

What is the most common functional pituitary adenoma?

Prolactinoma

6

What are the other kinds of functional pituitary adenomas and what are their effects?

Growth hormone secreting adenoma - GH causes increase in IGF which stimulates growth of bone, cartilage and connective tissue giving gigantism or acromegaly

ACTH secreting adenoma - Leads to hypercortisolism, Cushing's disease

7

What % of pituitary tumours are pituitary carcinoma?

<1%

8

List some causes of panhypopituitarism.

1y or metastatic tumours
traumatic brain injury
subarachnoid haemorrhage
surgery or radiation
granulomatous inflammation
infarction/ haemorrhage (Sheehans syndrome)
Hypothalamic lesions

9

Define panhypopituitarism.

Decreased secretion of all of the pituitary hormones.

10

What is a carinopharyngioma derived from?

Remants of Rathke's pouch (makes anterior pituitary)

11

List 5 things about carinopharyngiomas.

Slow growing, often cystic, may calcify
Some arise within the sella but most suprasellar
Bimodal incidence (5-15, 60-70s)
Headaches and visual disturbances
Excellent prognosis - benign tumour

12

What are the 2 kinds of diabetes insipidus?

Central or nephrogenic

13

What is central diabetes insipidus?

ADH deficiency
Can be caused by trauma (including surgery), tumours and inflammatory disorders of hypothalamus and pituitary

14

What is nephrogenic diabetes insipidus?

Renal resistance to ADH effects

15

What does SIADH secretion mean?

Syndrome of Inappropriate ADH secretion
Ectopic production of ADH - paraneoplastic syndrome

16

With Acromagaly, which cancer are you at increased risk of?

Colon cancer

17

How do non-functioning pituitary adenomas arise?

Sporadic or associated with MEN1

18

Give some causes of prolactinoma.

Physiological: pregnancy, breast feeding, stress, sleep
Drugs (dopamin antagonists, anti-psychotics, antidepressants, oestrogen, coccaine)
hypothyroidism (2y prolactinoma)
Pituitary stalk lesion

19

How does a prolactinoma arise in a female?

Early presentation
Galatorrhoea
Menstrual irregularity
Ammenorrhoea
Infertility

20

How does a prolactinoma present in a male?

Late presentation
Galactorrhoea
visualy field abnormality
headache
impotence or ED
Ant Pit malfunction

21

What investigations are required for a suspected prolactinoma?

Serum prolactin
MRI
Visual field (bitemporal hemianopia)
Pituitary function tests (several hormones)

22

How is a prolactinoma treated?

Dopamine agonists - Cabergoline, Metaclopramide - prolactin normaisation and tumour shrinkage

23

What treatment is required for acromegaly?

Pituitary surgery
Retest GTT – if still>1mcg then needs drugs:
Somatostain analogues: Octreotide
Dopamine agonists: Cabergoline
GH antagonist: Pegvisomant

24

How does acromegaly present?

Thickened skin and enlarged jaw and facial aspects
Sweating
Sleep apnoea/ snoring
Visual disturbance
Headaches – increased blood flow and tumour expansion

25

What causes acromegaly?

Anterior pituitary gland produces excess growth hormone

26

What is the definitive test for acromegaly?

glucose tolerance test: suppression test of GH – paradoxical rise in GH occurs: normal GH suppresses to 1mcg/l

27

What blood test can be useful in the aiding the diagnosis of acromegaly?

IGF1

28

What can panhypopituitarism lead to?

GH -- growth failure
TSH -- hypothyroidism
LH/FSH -- hypogonadism
ACTH -- Hypoadrenal (ife-threatening)
ADH -- Diabetes Insipidus

29

Give some symptoms and signs of panhypopituitarism.

Menstraul irregularities
Infertility/ impotence
Gynaecomastia (M)
Loss of facial hair (M)
Loss of axillary and pubic hair
hypothyroid faces
abdo obesity
dry skin and hair
growth retardation (children)

30

What drugs can be given for panhypopituitarism?

Thyroxine
Hydorcortisone
ADH
GH (rarely given)
OCP
Testosterone for males (Sustanon, testogel)

31

What are the risks of testosterone replacement?

Prostate enlargment (not cancer)
Polycythemia
Hepatitis (oral tabs only)

32

What can cause diabetes insipidus?

Familial – isolated or DIDMOAD
Acquired (idiopathic, RTA, surgery, skull #)
Rare (tumour, Sarcoid, meningitis, ext radiation)

33

What are the symptoms of DI?

Polyuria
Polydipsia
Signs of dehydration (sometimes)
Blurred vision (rarely)

34

What are the symptoms of Cushing's disease?

Weight gain (central)
HTN
Alopecia
Easily bruised
Back pain
Conjunctival oedema (chemosis)
proximal myopathy
thin skin
striae
facial plethora
acne
amenorrhoea
altered psyche

35

What causes primary Cushing's disease?

Adrenal adenoma
Pituitary adenoma
Ectopic ACTH (usually carcinoma - lung)

36

Name 3 causes of secondary Cushing's disease?

Steroid meds
Alcohol – pseudocushing’s
Depression

37

What screening tests are used for Cushing's disease?

Dexamethasone 1mg overnight
24hr urinary free cortisol
Morning & midnight cortisol

38

What test is used to provide a definitve diagnosis of Cushing's disease?

Low dose dexamethasone

39

When Cushing's disease is caused by a pituitary adenoma, is it likely to be a micro or macro adenoma?

microadenoma

40

When Acromegaly is caused by a pituitary adenoma, is it likely to be a micro or macro adenoma?

Macroadenoma

41

A pituitary adenoma = 1cm is known as what?

Mesoadenoma

42

What test is used to differentiate between the causes of Cushing's disease?

Short synacthen test

43

What are the 4 endocrine causes of HTN?

Phaechromocytoma
Cushing's
Conn's syndrome
Acromegaly

44

Chronic suppression of pituitary ACTH production and adrenal atrophy leads to what?

unable to respond to stress (illness/surgery)
need extra steroid when ill
CANNOT stop steroid suddenly - gradual

45

What treatment can be used for the different types of Cushing's disease?

Pituitary: hypophysectomy and external radiotherapy if recurrence
Adrenal: adrenalectomy
Ectopic: remove source or bilateral adrenalectomy

Metyrapone – if other Tx fails or while waiting for radio to work