Clinical Aspects of Pituitary Disease Flashcards
What are the hypersecretion tumours of the pituitary?
Growth hormone - acromegaly or gigantism
ACTH - cushing’s disease
Prolactin - hyperprolactinaemia
What are the hyposecretion conditions of the pituitary?
Anterior (FSH/LH, GH, ACTH, TSH)
Posterior (vasopressin)
What are the space occupying conditions caused by the piuitary?
Optic chiasmal compression
What are the clinical features of acromegaly?
Soft tissue overgrowth:
Spade like hands
Wide feet
Coarse facial features
Thick lips and tongue
Carpal tunnel syndrome
Sweating
Complications:
Headache
Chiasmal compression
Diabetes mellitus
Hypertension
Cardiomyopathy
Sleep apnoea
Accelerated OA
Colonic polyps
Headaches and weating are the most common symptoms of acromegaly
What is the treatment of acromegaly?
Somatostatin anologue
Surgery
Radiation therapy
What causes cushings syndrome?
Excess corticosteroids
What is the effect of cortisol on tissue, sodium and insulin?
Causes tissue breakdown - weakness of the skin, muscle and bone
Sodium retention - may cause hypertension and heart failure
Insulin antagonism - may cause diabetes mellitus
What are the high value symptoms and signs of cushing’s syndrome?
High value:
Skin atrophy
Spontaneous purpura
Proximal myopathy
Osteoporosis
Growth arrest in children
Intermediate value:
Pink striae
Facial mooning and hirsutism
Oedema
Non-specific:
Central obesity
Hypertension
What are the two types of cushing’s syndrome?
ACTH - dependant
Pituitary tumour (cushing’s disease)
Ectopic ACTH secretion (e.g lung carcinoid)
ACTH - Independant
Adrenal tumour (adenoma or carcinoma)
Corticosteroid therapy (asthma or IBD)
What is the clinical manifestation of hyperprolactinaemia?
Women:
Galactorrhoea (spontaneous flow of milk from the breast)
Menstrual irregularity
Infertility
Men:
Galactorrhoea
Impotence (unable to achieve erection or orgasm)
Visual field abnormalities
Headache
Extrraocular muscle weakness
Anterior pituitary malfunction
What are the physiological causes of hyperprolactinaemia?
Pregnancy
Lactation
Stress
What are the pharmacological causes of hyperprolactinaemia?
Dopamine depleting drugs
Dopamine antagonist drugs
What are the pathological causes of hyperprolactinaemia?
Primary hypothyroidism
Pituitary lesions (prolactinoma or ‘pituitary stalk pressure’)
What are the drugs which may cause hyperprolactinaemia?
Dopamine antagonists
Neuroleptics (chlorpromazine)
Anti-emitics (metoclopramide)
DA-depleting agents
Oestrogens
Some antidepresants
Homeopathic and herbal remedies
What are the clinical features of hypopituitarism in adults vs children?
Adults:
Tiredness, weight gain, depression, reduced libido, impotence, menstrual problems
Skin pallor
Reduced body hair
Children:
Reduced linear growth
Delayed puberty
Define diabetes insipidus
A disease in which the secretion of or response to the pituitary hormone vasopressin is impaired, resulting in the production of very large quantities of dilute urine, often with dehydration and insatiable thirst
What are the causes of diabetes insipidus?
Idiopathic - autoimmune hypophysitis
Post trauma
Metastatic carcimnoma
Craniopharyngioma
Other brain tumours (germinoma)
Rare causes (sarcoidosis)
What can cause bitemporal hemianopia?
Space occupying lesion of the pituitary
(pituitary adenoma)
How do we manage hypersecretion of pituitary tumours?
Dopamine agonists (prolactinoma)
Somatostatin anologues (acromegaly)
GH receptor antagonists (acromegaly)
How do we manage hyposecretion of pituitary?
Cortisol
T4 (thyroxine)
Sex steroids
GH
Desmopressin
What are the beneficial effects of somatostatin anologues in acromegaly?
- Improve soft tissue overgrowth, sweating, headache, sleep apnoea in most patients
- Normalise GH and IGF-1 levels in over 50% patients
- Induce tumour shrinkage in the majority
- Reduce morbidity & mortality from acromegaly
Give examples of somatostatin anologues
Octreotide
Lanreotide
What are the adverse effects of somatostatin anologues?
- 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)
Pituitary radiotherapy and surgery?
Pituitary radiotherapy:
use declining, acts slowly,
causes hypopituitarism
Pituitary surgery: especially for non-functional pituitary
tumours and Cushing’s disease
What hormones control release of prolactin?
Thyrotrophin releasing hormone increases release of prolactin
Dopamine (prolactin inhibiting factor) inhibits the release of prolactin and cancels the effects of thyrotrophin releasing hormone
Dopamine is constantly released in anyone that is not pregnant
What negative feedback mechanisms are activated as a result of too much prolactin?
Dopamine release is triggered
Gonadotrophin releasing hormone levels are reduced
What is the definition of a microprolactinoma and a macroprolactinoma?
What are the features of microprolactinoma?
Usually women with galactorrhoea
Amenorrhoea
Infertility
Serum prolactin less than 5000 mU/I
What is the treatment of microprolactinoma?
Cabergoline (dopamine receptor agonist)
Ovulatory cycles, fertility and normoprolactinaemia is restored in most cases
What is the response to dopamine agonist when there is macroprolactinoma?
- Rapid fall in serum PRL (hours)
- Tumour shrinkage (days/weeks)
- Visual improvement (often within days)
- Often recovery of pituitary function
80-90% tumours show these responses & most will shrink by at least one half
