Pituitary Disease (2) Flashcards
Pituitary Adenoma:
What does it mean if it’s functional?
What does it mean if it’s non-functional?
How does it present?
How is it managed?
➊ Produces hormones, small at presentation
➋ Doesn’t produce hormones, large at presentation
➌ • Headache
• Bitemporal hemianopia - compression of optic chiasm
• Diplopia - compression of CN 3/4/6
➍ Trans-sphenoidal surgery
Prolactinoma:
What is it?
How does it present?
How is it investigated?
→ What is seen?
How is it managed?
➊ Most common type of pituitary adenoma
➋ • Women - Oligomenorrhoea/amenorrhoea, Galactorrhoea, Infertility, Vaginal dryness
• Men - Erectile dysfunction, Reduced facial hair
• SOL - Headache, Bitemporal hemianopia, Diplopia
➌ • MRI brain
• Serum prolactin
→ • Microadenoma - lesions in the pituitary
• Macroadenoma - SOL
➍ • Cabergoline - dopamine agonist, which leads to a decrease in prolactin
• Transphenoidal surgery
Acromegaly:
What is it?
How does it present?
How is it investigated?
How is it managed?
➊ GH-secreting pituitary adenoma
➋ * Large hands and feet
* Joint pains
* Facial changes - Frontal bossing, Large protruding jaw, Macroglossia
* OSA
* SOL - Headache, Bitemporal hemianopia
* Organ dysfunction - LV Hypertrophy, HTN, DM
➌ * IGF-1 as the initial screening tool
* OGTT as confirmation of the diagnosis - Glucose load will fail to suppress GH
* MRI brain
* Old photos for comparison
➍ * Trans-sphenoidal surgery - 1st line
* Somatostatin analogues (e.g. Lanreotide) - blocks GH release
N.B. GH level isn’t a good diagnostic tool as it has a pulsatile release and fluctuates throughout the day
Cushing’s Syndrome:
What is it?
What is it’s most common cause?
→ What are its other causes?
How does it present?
What are the investigations to do?
How is it managed?
➊ Excess cortisol secretion from adrenal gland
➋ Cushing’s disease (ACTH-secreting pituitary adenoma)
→ • Ectopic ACTH secretion e.g. small-cell lung ca.
• Adrenal adenoma
• Exogenous steroids
➌ • Face - Round “moon-face”, plethoric, acne
• Thinning of hair and skin
• Abdominal striae
• Central obesity
• Buffalo Hump (fat pad on upper back)
• Easy bruising, poor skin healing
• Proximal myopathy
• Systemic - HTN, DM, LVH, Osteoporosis
➍ • Overnight DEXA suppression test - Failure to suppress cortisol in the morning suggests cushing’s
• 24 hr urinary cortisol
• Plasma ACTH
• MRI brain
➎ • Transphenoidal surgery
• Metyrapone as steroid-blocking therapy
N.B. Most pts require steroid replacement therapy following surgery
SIADH:
What is it?
What are its causes?
How does it present?
What are the investigations to do?
How is it managed?
→ Which complication should be avoided here? How?
➊ Excessive ADH production, which leads to lots of water reabsorption - This leads to both high urine osmolality and a euvolemic hyponatraemia (diluted blood)
➋ • Pituitary tumour
• Malignancy, esp small-cell lung cancer
• Medications e.g. thiazide diuretics, carbamazepine, vincristine, NSAIDs
• Infection e.g. pneumonia
• Meningitis
• Idiopathic
➌ • Muscle aches and cramps
• N+V
• Fatigue
• Confusion, coma
• Seizures
➍ • U&Es
• Plasma osmolality - will be low
• Urine osmolality - will be high
• Urine sodium - will be high
• MRI brain
➎ Fluid restriction
→ Central Pontine Myelinolysis - Avoid by correcting sodium slowly i.e. < 10 mmol/L/day
N.B. Tolvaptan is an ADH receptor blocker that can be used here
Diabetes Insipidus:
What are its 2 types?
→ What can cause it?
How does it present?
What are the investigations to do?
How is it managed?
➊ • Cranial - Lack of ADH
→ Idiopathic, tumour, trauma, brain infection
• Nephrogenic - Kidneys fail to respond to ADH
→ Iatrogenic e.g. lithium, genetics, electrolyte imbalance
➋ • Polyuria
• Polydipsia
• Hypernatraemia - lethargy, thirst, weakness, confusion
➌ • U&Es
• Plasma osmolality - will be high
• Urine osmolality - will be low
• Urine sodium - will be low
• Fluid deprivation test
‣ Cranial DI - urine osmolality increases after desmopressin is given
‣ Nephrogenic DI - urine osmolality stays low after desmopressin is given
• MRI brain
➍ Desmopressin
