Pituitary tumours (E&M)

Question 1

Define pituitary tumours.

Answer 1

Benign tumours that arise sporadically from the anterior pituitary gland

Question 2

What are the causes of pituitary tumours? (2)

Answer 2

• most occur sporadically
• multiple endocrine neoplasia (MEN) type 1 - associated with 3Ps (pituitary tumour, parathyroid adenoma, pancreatic tumour - insulinoma)

Question 3

What symptoms would point towards MEN Type 1 (cause of pituitary tumours)? (3)

Answer 3

• peptic ulceration
• galactorrhoea
• hypercalcaemia

Question 4

What are two ways of classifying pituitary tumours?

Answer 4

• size:
  
  • microadenoma (</=10mm)
  • macroadenoma (>10mm)
• hormonal status - functional (secretes hormones) vs non-functional (does not produce excess hormones):
  
  • prolactinoma (prolactin-secreting)
  • acromegaly (GH-secreting)
  • Cushing’s disease (ACTH-secreting

Question 5

How can non-functioning pituitary tumours spread? (3)

Answer 5

• suprasellar extension towards optic chiasm (–> bitemporal hemianopia)
• lateral extension into cavernous sinuses (CN palsies)
• downward extension into sphenoid

Question 6

What is carcinoid syndrome?

Answer 6

Due to neuroendocrine tumour (NET) secreting serotonin

Question 7

What are the clinical features of carcinoid syndrome? (6)

Answer 7

• flushing
• diarrhoea
• SOB
• abdominal pain
• Cushing’s-like symptoms due to ACTH secretion
• cardiac problems - tricuspid insufficiency and pulmonary stenosis

Question 8

What is the first-line investigation for carcinoid syndrome?

Answer 8

Urinary 5-HIAA

Question 9

What is the first-line management for carcinoid syndrome?

Answer 9

Octreotide (somatostatin analogue)

Question 10

What are the clinical features of a non-functioning pituitary tumour? (4+3)

Answer 10

• headache
• bitemporal hemianopia - due to pressure on the optic chiasm
• panhypopituitarism - tumour may compress other parts of pituitary –> generalised panhypopituitarism:
  
  • low ACTH –> tiredness, postural hypotension
  • low FSH/LH –> amenorrhoea, infertility, loss of libido, small testes, loss of axillary and pubic hair
  • low TSH –> feeling cold, constipation
• hyperprolactinaemia (due to low dopamine) –> acne, hirsutism, amenorrhoea, galactorrhoea, gynaecomastia

Question 11

How can bitemporal hemianopia in non-functioning pituitary tumours be classified further? (2)

Answer 11

• if upper quadrant defect > lower quadrant defect –> inferior chiasmal compression caused by a pituitary tumour
• if lower quadrant defect > upper quadrant defect –> superior chiasmal compression caused by a craniopharyngioma

Question 12

What are some features of panhypopituitarism, seen in non-functional pituitary tumours? (3)

Answer 12

• low ACTH –> tiredness, postural hypotension
• low FSH/LH –> amenorrhoea, infertility, loss of libido, small testes, loss of axillary and pubic hair
• low TSH –> feeling cold, constipation

Question 13

How do prolactinomas present (pituitary tumours) in men vs women?

Answer 13

• men - impotence, loss of libido, galactorrhoea
• women - amenorrhoea, infertility, galactorrhoea, osteoporosis

Question 14

What additional macroadenoma signs can you see in prolactinomas? (3)

Answer 14

• headache
• visual disturbances
• hypopituitarism signs - prolactinoma compresses pituitary stalk

Question 15

How would acromegaly (pituitary tumours) present? (5)

Answer 15

• OSA
• excess sweating
• large tongue (macroglossia)
• increase in hand and shoe size
• cardiomyopathy
• (coarsening of facial features, prognathism, large nose)

Question 16

What is the first-line investigation done for pituitary tumours?

Answer 16

Brain MRI (identify if micro- or macroadenoma)

Question 17

What specific bloods do we do for pituitary tumours?

Answer 17

Pituitary blood profile - to determine whether mass is functioning or non-functioning

• GH
• prolactin
• ACTH
• FSH
• LH
• TFTs

Question 18

What investigations would we do for suspected acromegaly (pituitary tumour)?

Answer 18

1. initial: serum IGF-1 (elevated)
2. then, as diagnostic investigation: OGTT with serial GH measurements - would see a paradoxical rise (no suppression) in GH following glucose load

• serum GH is less reliable as an Ix as it is pulsatile

Question 19

What investigation do we do for suspected prolactinoma (pituitary tumour)?

Answer 19

Serum prolactin - will be high

Question 20

What can cause lactotroph hyperplasia?

Answer 20

Pregnancy

Question 21

What other investigation can we do for pituitary tumours?

Answer 21

Visual field testing - identify bitemporal hemianopia

Question 22

How do we manage a microadenoma or asymptomatic macroadenoma (pituitary tumours)?

Answer 22

Observation
(Consider hormone replacement, consider trans-sphenoidal surgery)

Question 23

How do we manage a symptomatic macroadenoma (pituitary tumour)?

Answer 23

Trans-sphenoidal pituitary surgery

Consider hormone replacement, dopamine agonist or somatostatin analogue (octreotide)

Question 24

What is the first-line management of pituitary apoplexy (acute)?

Answer 24

Glucocorticoid +/- levothyroxine

Question 25

What is the management plan for prolactinomas (pituitary tumours)?

Answer 25

• 1st line: cabergoline/bromocriptine (dopamine agonists)
• 2nd line: surgery (trans-sphenoidal if >1cm)
• radiotherapy

Question 26

What is the management plan for acromegaly (pituitary tumours)?

Answer 26

• 1st line: trans-sphenoidal surgery
• 2nd line: octreotide (somatostatin analogue)

Question 27

What are some complications of pituitary tumours? (6)

Answer 27

• hypopituitarism
• diabetes insipidus
• meningitis
• pituitary apoplexy
• visual loss
• prolactinoma - reduced fertility, osteoporosis

Question 28

Describe the prognosis of pituitary tumours.

Answer 28

Patients with clinically non-functioning pituitary adenomas generally have a good prognosis