Pituitary and adrenal disease Flashcards
Pituitary hormones.
a) Anterior hormones, their cells and function
b) Hypothalamic hormones that stimulate/inhibit them
c) Posterior hormones and their function
a) - Gonadatrophs (FSH, LH): stimulate gonads to release oestrogen, progesterone and testosterone
- Corticotrophs (ACTH): stimulates cortisol release
- Thyrotrophs (TSH): stimulates T4 release
- Somatotrophs (GH): stimulates IGF-1 and bone growth
- Lactotrophs (prolactin): stimulate mammary glands
b) - GnRH: stimulate FSH and LH
- CRH: stimulates ACTH
- TRH: stimulates TSH
- Somatostatin: inhibits GH (useful in acromegaly)
- Dopamine: inhibits prolactin (useful in prolactinoma)
c) Produced in the hypothalamus:
- Oxytocin: ‘happy’ hormone, stimulates uterine contractions in labour
- Vasopressin (ADH): increases AQP-2 expression and causes water retention in collecting ducts
Pituitary adenoma.
a) 3 ways in which they may cause problems
b) Most common types
c) Rare types
d) Presentation
e) Differentials
f) Essential investigations
g) Management - medical vs. other
h) Complications of surgery
a) - Excessive hormone production
- Local mass effects of the tumour
- Inadequate hormone production by the remaining pituitary gland (hypopituitarism)
b) - Non-functioning adenoma
- Prolactinoma
- GH-secreting tumour (causing acromegaly)
- ACTH-secreting tumour (causing Cushing’s disease)
c) - TSH-secreting adenoma
- LH/FSH-secreting adenoma
d) - Headache: usually retro-orbital or bitemporal
- Visual field defects (classically bitemporal)
- Raised ICP
- Hormonal excess (eg. galactorrhoea, infertility, weight gain, excessive bone growth)
- Hormonal deficiency (eg. pubertal delay, growth failure, infertility, adrenal failure, hypothyroid, etc.)
- Hypothalamic disease - disorders of homeostasis (eg. temperature, appetite and thirst regulation)
e) - Other tumours (eg. craniopharyngioma, meningioma)
- Other causes of headache/ visual field loss/ raised ICP
- Other endocrine: disorders of thyroid, adrenal, gonads, hypothalamus, etc.
f) - Visual fields testing
- Prolactin blood test
- Other pituitary function tests:
- MRI pituitary (gold-standard)
g) - Must not drive / inform DVLA if visual field defect
- Small non-functioning: watch and wait
- Prolactinomas: dopamine-agonist (bromocriptine, cabergoline)
- GH adenomas: somatostatin-analogues (lanretoide, octreotide)
- Radiotherapy
- Surgery (transphenoidal)
h) - Diabetes insipidus
- Hypopituitarism
Nelson’s syndrome.
a) What is it?
b) How does it present?
a) - Enlargement of the pituitary gland, with excessive ACTH production, post-adrenalectomy.
- Caused by inadequate negative feedback on pituitary gland due to reduced steroid production
b) - Mass effects: headache, bitemporal hemianopia
- Increased ACTH: skin pigmentation, amenorrhoea
Waterhouse-Friderichsen syndrome.
a) What is it?
b) What is it usually caused by?
a) Adrenal gland failure due to bleeding into the adrenal glands
b) Severe bacterial infection (eg Neisseria meningitidis)
Acromegaly.
a) Usual cause
b) Appearance changes
c) Other features/complications
d) Investigations (diagnostic)
e) Investigations (other)
f) Management
a) GH-secreting adenoma (if occurs before growth plates have fused - leads to gigantism)
b) - Enlargement of hands and feet
- Frontal bossing, nose thickening
- Macroglossia
- Growth of the jaw (prognathism)
- Coarsening of facial features
c) - Sweaty, oily skin
- CV: HTN, CCF, LVH, arrhythmias
- Diabetes
- Hypopituitarism
- Cancer: thyroid, colon
d) - IGF-1 screening test (high)
- Then do an OGTT (in normal people leads to GH/IGF-1 inhibition, but remains high in acromegaly)
e) - Other bloods: cholesterol, diabetes
- Pituitary function tests
- Visual fields
- MRI pituitary
f) - Medical: somatostatin analogues (lanreotide, octreotide)
- Surgical (required in most): transphenoidal
Hyperprolactinaemia.
a) Causes
b) Presentation
c) Prolactinoma - classification
d) Investigations
e) Medical management and side effects
f) Other management options
a) - Physiological: pregnancy, breastfeeding, exercise, stress response
- Intracranial: prolactinoma, head injury, surgery
- Drug-induced: dopamine-antagonists (eg. haloperidol)
- Endocrine: PCOS, Cushing’s, hypothyroid
b) - Women: amenorrhoea, infertility, galactorrhoea
- Men: impotence, gynaecomastia, infertility
- Children: delayed growth/puberty, hypogonadism
- Mass effect: headache, visual fields
c) - Microadenomas: < 10 mm (< 1 cm)
- Macroadenomas: > 10 mm (> 1 cm)
d) - Pregnancy test
- Serum prolactin: < 400 = normal, > 5000 = definite prolactinoma (usually need 2 samples > 400 for diagnosis; don’t stress patient)
- Visual fields
- Pituitary function tests
- MRI pituitary
e) - Dopamine agonists (bromocriptine, carbergoline), may cause pathological gambling, loss of impulse control, etc.
f) - Transphenoidal surgery and RT
- Removing causes (drug-induced)
- Oestrogen/testosterone replacement
- Bone protection (BPs)
Cushing syndrome.
a) What is it?
b) Causes
c) Appearance changes
d) Other clinical features
e) 3 diagnostic tests
f) Other investigations
g) Management
a) A syndrome of excess production (endogenous) or administration (exogenous) glucocorticoid levels
b) - Excess corticosteroid use (suppressed ACTH)
- Pituitary adenoma: excess ACTH production (Cushing disease)
- Adrenal adenoma or carcinoma (suppressed ACTH)
- Ectopic-ACTH production (eg. SCLC, other cancer)
c) - Truncal obesity, supraclavicular fat pads, buffalo hump, weight gain, moon facies, oedema
- Proximal muscle wasting and weakness.
- Skin atrophy, striae, bruising, hirsutism, acne, pigmentation (if ACTH-dependent)
d) - CVD: diabetes, HTN
- Endocrine: reduced libido, menstrual irregularity, thirst, polydipsia/uria, growth failure (children), hypothyroid
- Psych: depression, emotional lability.
- MSK: weakness, osteopenia or osteoporosis.
- Infections, impaired wound healing
e) - 24-hour urinary free cortisol
- 1 mg overnight dexamethasone suppression test
- Late-night salivary cortisol
f) - Bloods: hypokalaemia, hypernatraemia, hyperglycaemia
- ACTH (low in exogenous/adrenal cause; high in ACTH-secreting adenoma/ectopic-ACTH)
- Imaging: MRI pituitary, ?CT abdo/chest (malignancy, adrenal adenoma)
g) - Medical: cortisol synthesis inhibitors - Metyrapone, ketoconazole
- Surgical (definitive treatment): resect adenoma*, etc.
*Note: often for Cushing disease (ACTH-secreting pituitary adenoma), bilateral adrenalectomy is done to lower cortisol levels - this can cause Nelson syndrome
Hyperaldosteronism.
a) Causes - primary vs secondary
b) Classical clinical features
c) Aldosterone and renin studies
d) Other investigations
e) Management
a) Primary (low renin)
- Adrenal adenoma (Conn’s)
- Bilateral adrenal hyperplasia)
- Adrenal carcinoma
Secondary (high renin):
- Diuretics
- Renovascular - RAS, CoA (hypertensive)
- CCF, nephrotic syndrome, liver failure
- Rarely: Gitelman’s, Barrter’s, renin-secreting tumours
b) - Hypertension, metabolic alkalosis, low K+, high Na+
- Symptoms: polyuria and polydipsia (due to reduced ability to concentrate urine), weakness (due to low K+)
c) Renin and aldosterone.
- if renin low, request aldosterone levels and investigate for adrenal cause
- if renin high, investigate for renal cause (eg. RAS - renal USS) or consider diuretic/overload cause
- Salt loading aldosterone + renin levels (salt should suppress aldosterone in healthy people)
- Lying/standing aldosterone + renin levels
- Aldosterone:renin ratio (> 1000 is diagnostic)*
d) - U+Es, BP
- Imaging: CT abdo (adrenal adenoma, etc.), renal USS (if renal cause suspected, eg. RAS)
*note: drugs like ACE/BBs/diuretics can affect these results so ideally should be stopped prior to testing
e) - Aldosterone antagonists: spiro/eplerenone
- Surgery: definitive management in Conn’s
Adrenal insufficiency.
a) Causes - primary and secondary
b) Presentation
c) Diagnostic tests
d) Other investigations and results
e) Management - non-drug, drug and monitoring
a) Primary (Addison’s) - raised ACTH
- Autoimmune (85%) - antibodies against 21-hydroxylase
- Congenital - CAH
- Critical illness (eg. sepsis, trauma, etc.)
- Other - infection (eg. TB, HIV), haemorrhage (eg. WFS), removal, invasion (eg. malignant, infiltrative)
Secondary - low ACTH
- exogenous steroid use* (commonest secondary cause)
- other - pituitary failure, hypothalamic failure, etc.
*Any dose equivalent to prednisolone > 7.5 mg
for 3 weeks or more - at risk of secondary adrenal insufficiency if stopped abruptly or intercurrent infection
b) Usually acute (may be chronic)
- Hypotension, shock, abdominal pain, vomiting, weakness, salt-cravings, muscle cramps, confusion
- Signs: postural drop, hyperpigmentation
- Features of other AI disease (eg. thyroid, DM, vitiligo)
c) - 9am serum cortisol (< 100 = abnormal)
- Serum ACTH (raised in primary; low-norm in secondary)
- Synacthen test
- Adrenal auto-antibodies (21-hydroxylase)
d) - BP (low)
- U+E (low Na+, high K+)
- Venous gas (acidosis)
- Pituitary function tests
- Imaging - MRI pituitary, CT adrenals, etc.
e) Patient education.
- Importance of regular steroids
- Doubling steroid dose when unwell
- Steroid card, emergency kit, etc.
- Signs of an Addisonian crisis
Drugs.
- Hydrocortisone
- Fludrocortisone
Monitoring.
- For signs of under/over treatment
- For complications - bones, HTN, glucose
- Other AI diseases - check TFTs, glucose, coeliac, etc.
Pituitary failure.
a) Post-partum cause
b) Acute haemorrhage
a) Sheehan’s - postpartum pituitary necrosis (usually caused by massive PPH)
b) Pituitary apoplexy:
- sudden onset headache, vomiting, visual issues, ptosis
- Rx: hydrocortisone IV
