Pituitary Gland Clinical Flashcards
What condition does hypersecretion of GH cause?
Acromegaly (gigantism)
What condition does hypersecretion of ACTH cause?
Cushing’s disease
What condition does hypersecretion of prolactin cause?
Hyperprolactnaemia
What hormones can be hyposecreted by the anterior pituitary gland?
- FSH/LH
- GH
- ACTH
- TSH
What hormone can be hyposecreted by the posterior pituitary?
Vasopressin
What can a SOL of the pituitary gland lead to?
Optic chiasmal compression
What are the clinical soft tissue overgrowth features of acromegaly?
- spade like hands (rings)
- wide feet (shoes)
- coarse facial features
- thick lips & tongue
- carpal tunnel syndrome
- sweating
What are the possible complications of acromegaly?
- headache
- chiasmal compression
- diabetes mellitus
- hypertension
- cardiomyopathy
- sleep apnoea
- accelerated OA
- colonic polyps & CA
How is acromegaly diagnosed?
- oral glucose tolerance test
- can GH be suppressed?
- is insulin-like growth factor-1 (IGF1) elevated?
- is the rest of the pituitary function normal?
- is there a pituitary tumour on MRI?
- is vision normal?
What is Cushing’s syndrome a result of?
Excess corticosteroids
What type of hormone is cortisol?
Catabolic
What physiological changes does excess cortisol lead to?
tissue breakdown
- causes weakness of skin, muscle and bone
sodium retention
- may cause hypertension and heart failure
insulin antagonism
- may cause diabetes mellitus
What are the high value signs and symptoms of Cushing’s syndrome?
- skin atrophy
- spontaneous purpura
- proximal myopathy
- osteoporosis
- growth arrest in children
What are the intermediate value signs and symptoms of Cushing’s syndrome?
- pink striae
- facial mooning and hirsutism
- oedema
What are the non-specific signs and symptoms of Cushing’s syndrome?
- central obesity
- hypertension
What are the ACTH-dependent causes of Cushing’s syndrome?
- pituitary tumour (Cushing’s disease)
- ectopic ACTH secretion (e.g. lung carcinoid)
What are the ACTH-independent causes of Cushing’s syndrome?
- adrenal tumour (adenoma or carcinoma)
- corticosteroid therapy (eg for asthma, IBD)
How can hyperprolactinaemia manifest itself in a women?
- galactorrhoea (30-80%)
- menstrual irregularity
- infertility
How can hyperprolactinaemia manifest itself in a man?
- galactorrhoea (<5%)
- impotence
- visual field abnormalities
- headache
- extrocular muscle weakness
- anterior pituitary malfunction
What are the physiological causes of hyperprolactinaemia?
- pregnancy
- lactation
- stress
What are the pharmacological causes of hyperprolactinaemia?
DA depleting and DA antagonist drugs
What are the pathological causes of hyperprolactinaemia?
- primary hypothyroidism
- pituitary lesions (prolactinoma or pituitary stalk tumour)
What drugs may cause hyperprolactinaemia?
dopamine antagonists
- neuroleptics (eg chlorpromazine)
- anti-emetics (eg metoclopramide)
DA depleting agents
Oestrogens (not in OCP dosage)
Some antidepressants
What are the clinical features of hypopituitarism in adults?
- tiredness
- weight gain
- depression
- reduced libido, impotence, menstrual problems
- skin pallor
- reduced body hair
What are the clinical features of hypopituitarism in children?
- reduced linear growth
- delayed puberty
Cranial Diabetes Insipidus: differential diagnosis
- idiopathic (autoimmune hypophysitis)
- post trauma including pituitary surgery
- metastatic carcinoma
- craniopharnygioma
- other brain tumours (germinoma)
- rare causes (sarcoidosis)
What investigation can be carried out for cranial diabetes insipidus?
Water deprivation test
How should pituitary hypersecretion be managed?
- dopamine agonists (prolactinoma)
- somatostatin analogues (acromegaly)
- GH receptor antagonist (acromegaly)
How should pituitary hyposecretion be managed?
- cortisol, T4, sex steroids, GH
- desmopressin
How should pituitary tumours be managed?
- surgery (most transsphenoidal)
- radiotherapy
When is pituitary surgery usually an option?
Non-functional pituitary tumours and Cushing’s disease
What are the beneficial effects of somatostatin analogues in acromegaly?
improves
- soft tissue overgrowth
- sweating
- headache
- sleep apnoea
Normalise GH and IGF-1 levels in over 50% of patients
Induce tumour shrinkage in the majority
Reduce morbidity and mortality
What are the adverse effects of somatostatin analogues?
- nausea, cramps, diarrhoea, flatulence (often transient)
- cholesterol gallstones occur in 20-30% (mostly asymptomatic)
- slow release preparations require monthly IM/SC injections
- high cost (£6-12,000 annually)
Why is pituitary radiotherapy use declining?
- acts slowly
- causes hypopituitarism
What is the size range for micoprolactinoma?
<10mm
What is the treatment for microprolactinoma?
dopamine agonists
What can cabergoline restore in micoprolactinoma?
- normoprolactinaemia
- ovulatory cycles
- fertility restored in 70-90%
What is the usual presentation of someone with micoprolactinoma?
Usually women with
- galactorrhoea,
- amenorrhoea
- infertility
- serum PRL <5000mU/I (N<500)
What happen to most microprolactinomas?
Most shrink
What is the size range for macroprolactinomas?
> 10mm
What is the typical response of a macroprolactinoma to a dopamine agonist?
- rapid fall in serum PRL (hours)
- tumour shrinkage (days/weeks)
- visual improvement (often within days)
- often recovery of pituitary function
What is the management for acromegaly?
Monthly injections of slow-release octreotide and lanreotide
