The Pituitary Gland Clinical Case & Discussion Flashcards
What disorders does hypersecretion of each of growth hormone, ACTH and prolactin correspond to?
GH hypersecretion - Acromegaly
ACTH - Cushing’s disease
Prolactin - hyperprolactinaemia
What are some clinical signs of acromegaly?
- “Spade like” hands
- Wide feet
- Coarse facial features
- Thick lips and tongue
- Carpal tunnel syndrome
- Sweatin
- Pronounced jaw and brow ridges
- Increased interdental spacing
What are some complications associated with acromegaly?
- Headache
- Chiasmal compression
- Diabetes mellitus
- Hypertension
- Cardiomyopathy
- Infertility
- Sleep apnoea
- Accelerated osteoarthritis
- Colonic polyps and cancer
Investigations for acromegaly?
- OGTT: failure of GH to be suppressed after glucose
- IGF-1 levels (elevated in acromegaly)
- MRI pituitary
- Visual fields / fasting glucose / pituitary hormone screen
What causes Cushing’s Syndrome? Pituitary related causes?
- Hypersecretion of cortisol from adrenal cortex
- Oversecretion of ACTH from pituitary (Cushing’s disease) can cause Cushing’s Syndrome
What does an excess of cortisol result in?
- Tissue breakdown (weak skin, muscle, bone)
- Sodium retention (hypertension & HF)
- Insulin antagonism
Symptoms of Cushing’s Syndrome?
- Skin atrophy
- Spontaneous purpura (blood spots on skin)
- Proximal myopathy
- Osteoporosis
- Growth arrest (in children)
- Hirsutism (inappropriate hair growth)
- Pink striae
What are some ACTH-independent causes of Cushing’s Syndrome?
- Adrenal tumours
- Corticosteroid therapy
What is galactorrhoea?
Excessive or inappropriate production of milk
Symptoms of hyperprolactinaemia in women?
- Galactorrhoea
- menstrual irregularity
- Infertility
Symptoms of hyperprolactinaemia in men?
- Galactorrhoea
- Impotence
- Visual field abnormality
- Headache
- Extraocular muscle weakness
- Anterior pituitary malfunction
Causes of hyperprolactinaemia?
- Pregnancy
- Lactation
- Stress
- Dopamine depleting / antagonistic drugs
- Hypothyroidism
- Pituitary lesions
What are some drugs that may cause hyperprolactinaemia?
- Dopamine antagonists (neuroleptics / anti-emetics)
- Dopamine depleting agents
- Oestrogens
- Some antidepressants
What are some clinical manifestations of hypopituitarism in adults?
- Tiredness
- Weight gain
- Depression
- Reduced libido
- Impotence
- Menstrual problems
- Skin pallor
- Reduced body hair
What are some clinical manifestations of hypopituitarism specific to children?
- Reduced linear growth
- Delayed puberty
Common clinical sign of pituitary issues?
- Visual field changes
What is Cranial Diabetes Insipidus?
- Where the hypothalamus (secretion by ant. pituitary) doesn’t produce enough ADH
- Causes dilute urine and increased thirst
What can be a good sign to look for showing pituitary enlargement on MRI?
- Invasion into the cavernous sinus space
- Cavernous sinuses appear much smaller than usual
What type of visual field defect is commonly associated with pituitary enlargement? Why?
- Bi-temporal hemianopia
- Loss of outer half of both left and right visual field, bc nasal fibres cross over at chiasm and so are compressed
- Nasal fibres responsible for temporal vision and vice versa, bc of the shape of the retina
Pharmacological management of hyperprolactinaemia?
- Dopamine agonist
Pharmacological management of acromegaly?
- Somatostatin analogues
- GH antagonists
What type of surgery is often done when needed for pituitary tumours? Brief description?
- Transsphenoidal surgery
- Endoscope / surgical instruments are put through the nose and enter the cranium via drilling through the sphenoid bone at the nasal cavity
What are some of the beneficial effects of somatostatin analogue treatment in acromegaly?
- Improve soft tissue overgrowth, sleep apnoea, sweating and headache in most patients
- Normalize GH and IGF-1 in approx. 50% of patients
- Induce tumour shrinkage in many
- Reduce morbidity and mortality
Other than surgery what treatments can be effective in pituitary tumours?
- Hormone supplementation / hormone antagonists
- Hyper-activation of certain glands causes hyperplasia, if antagonist to activating hormone given then less activation of the gland, and so the gland will shrink
What are octreotide and lanreotide? How are they administered and to treat what condition?
- Somatostatin analogues
- Subcutaneous / intramuscular injections
- treat acromegaly
Adverse effects of somatostatin analogues?
- Nausea / cramps / diarrhoea / flatulence
- Cholesterol gallstones in 20-30%
(treatment can be expensive)
