Pituitary Adrenal Disease Flashcards
What are the causes of seller masses?
Benign tumours: -pituitary adenoma -craniopharyngioma -meningioma Malignant tumours: -primary (vanishingly rare) -metastatic tumours (lung, breast) Cysts: Rathke's cleft, arachnoid, dermoid Lymphocytic hypophysitis Carotid aneurysm
What are the local effects of pituitary tumours?
- Headaches
- ->a) stretching of dura by tumour
- ->b) hydrocephalus (rare).
- Visual field defects (nasal retinal fibres compressed)
- Cranial nerve palsies and temporal lobe epilepsy (lateral extension of tumour)
- CSF rhinorrhea (downward extension of tumour)
What are the types of pituitary adenoma?
Prolactinoma - prolactin secreting
Acromegaly - GH secreting
Cushing’s - ACTH secreting
RARE: TSH secreting, Gonadotrophin secreting (FSH and LH).
Non funtioninig - just mass effect features but no hormone disruption.
What are the symptoms of prolactinoma in female?
- Galactorrhoea
- Hypogonadism - infertility + amenorrhoea or oligomenorrhea
What are the symptoms of prolactinoma in males?
- Hypogonadism - decreased libido, infertility, impotence, gynaecomastia.
- Rarely galactorrhoea.
What is the treatment for prolactinoma?
Dopamine agonists usually reduce tumour size and prolactin secretion e.g. bromocriptine, carbergoline.
What are the causes of acromegaly?
> Common: GH secreting pituitary adenoma
Rare:
-GH secreting extra pituitary tumour.
-GHRH hormone secreting tumour.
What are the clinical features of acromegaly?
- Insidious onset
- Enlarged jaw, hands and feet (dental problems, tight rings, increased shoe size).
- Coarsening facial features, enlarged frontal bones and nose.
- Thickened skin
- Enlargement of tongue, deepening of voice.
Investigations in suspected acromegaly?
- GH biochem: Increased
- OGTT: Failure to suppress GH w/ OGTT
- Increased IGF1 / Somatomedin C
- Diabetes or impaired OGTT
- CT/MRI: pit tumour
What is the treatment for acromegaly?
1’: transphenoidal hypophysectomy to remove tumour
Surgical resection unsuccessful:
- radiotherapy
- octreotide: long acting prep every 1/12
- bromocriptine
What is the size cut off for pituitary adenoma macro v micro?
10mm macro
What are the causes of Cushing’s syndrome?
- ACTH dependent Cushing’s syndrome:
- Cushing’s
- ectopic ACTH
- ectopic CRF.
- ACTH-independent Cushing’s syndrome:
- adrenal adenoma
- adrenal carcinoma
- micronodular hyperplasia
- macronodular hyperplasia.
What are the clinical features of Cushingoid appearance??
- Obesity: redistribution of weight centrally, moon face, buffalo hump, wasting of buttocks.
- Skin: atrophy of epidermis; thin skin, plethoric face, easy bruising, striae.
- Hirsutism
What are the major AEx of bromocriptine?
N/V, postural dizziness.
What are the neuropsychiatric clinical features of Cushing’s?
- Depressed mood/ crying
- decreased concentration and memory;
- insomnia
- decreased libido.
What are the MSK alterations of Cushing’s?
- Proximal myopathy
- Osteopaenia: crush fractures of vertebrae.
What are the metabolic features of Cushing’s?
- Diabetes 25%;
- glucose intolerance 75%
What are the investigations and expected results in Cushing’s syndrome?
- FBE: Hb high normal; WCC slightly elevated, decreased neutrophils
- Electroytes: hypokalemia and metabolic alkalosis in ectopic ACTH.
- Hyperglycemia: due to insulin resistance
- Increased Ca2+ absorption and hypercalciuria
How is Cushing’s diagnosed?
- 24h urine free cortisol
- Overnight dexamethasone suppression test.
How is pathological cause of Cushing’s determined?
ACTH:
- if suppressed, likely adrenal cause.
- Normal or elevated: likely pituitary dependent.
- Very high, likely ectopic ACTH.
Describe the 4 major forms of Cushing’s syndrome.
- Pituitary Cushing Syndrome
- Adrenal Cushing syndrome
- Paraneoplastic Cushing Syndrome
- Iatrogenic Cushing syndrome
Pituitary dependent Cushing’s treated?
Transphenoidal hypophysectomy to remove tumour.
How is adrenal adenoma or carcinoma Cushing’s treated?
Adrenal surgery
How is ectopic ACTH or CRF treated?
Treat the tumour associated with the hormone production.
What are the causes of adrenocortical insufficiency?
- Hypopituitarism: Insufficient section of ACTH by pituitary
- Addison’s Disease: Destruction of adrenal glands
What are the clinical features of primary Addison’s disease?
- Dark skin and mucosae
- High potassium
- Low sodium
- Metabolic acidosis
- Associated with primary hypothyroidism, DMI, vitiligo, near defects
What are the associated symptoms of Addison’s disease?
-Weakness, fatigue, myalgia, arthralgia
-weight loss,
-hypotension, postural dizziness
-salt craving.
GI: N/V/D and GI pain.
What is the aetiology of primary adrenocortical insufficiency?
- AI: AI associated atrophy
- Infection: TB, fungi (histoplasmosis, coccidiomycosis, HIV and AIDS)
- Infiltration: metastatic carcinoma
- Haemorrhage/infarction
- Drugs: inhibit cortisol/increase cortisol metabolism
- Adrenoleukodystrophy
Which drugs can lead to primary adrenocortical insufficiency?
- Inhibit cortisol: ketoconazole, megestrol acetate
- Increase cortisol metabolism: rifampin, phenytoin, barbituates, heparin, coumadin
What are the expected electrolyte disturbances of Addison’s disease?
- Hyponatremia
- Hyperkalemia
- Moderate acidosis
- Increased urea
-Hypoglycaemia
Ix for Addison’s disease?
- Serum cortisol - low
- ACTH - high
- Synacthen test (ACTH infusion)
- Adrenal antibodies (17hydroxylase enzyme Abs)
- Adrenal imaging - calcification or enlargement of adrenals (TB or infiltration)
What is the management of Addisonian Crisis?
- Hydrocortisone 100mg IV 6hrly
- Fluid replacement - IV normal saline
- Glucose if hypoglycaemic
What is long term Addison’s disease management?
GLUCOCORTICOIDS:
- Cortisone acetate 25mg/12.5mg
- Dexamethasone 0.25mg bd
- Prednisolone 5mg daily
MINERALOCORTICOIDS
-Fludrocortisone 0.1mg daily
What is Conn’s syndrme?
Excess aldosterone from adrenal cortex
What is a phaechromocytoma?
Tumour of chromaffin cells located in adrenal medulla; derived from neural crest cells.
Results in catecholamine excess.
What are the two major complications of acromegaly?
- Bowel cancer: excess GH stimulates polyp growth - may become cancerous.
- Cardiac: cardiac hypertrophy (ischaemic change, HOCM)
Pituitary dependent Cushing’s treated?
Transphenoidal hypophysectomy to remove tumour.
How is adrenal adenoma or carcinoma Cushing’s treated?
Adrenal surgery
What are the two major complications of acromegaly?
- Bowel cancer: excess GH stimulates polyp growth - may become cancerous.
- Cardiac: cardiac hypertrophy (ischaemic change, HOCM)
What is the role of inferior petrosal sinus sampling?
Sample central and peripheral cortisol level to confirm pituitary adenoma visualised on MRI is the same site from which excess cortisol is coming.
What are the types of primary aldosteronism?
(1) - Aldosterone producing adenoma
(2) - Bilateral idiopathic hyperaldosteronism
(3) - Glucocorticoid suppressible hyperaldosteronism
(4) - aldosterone producing adrenal Ca
What is the clinical triad of primary aldosteronism?
- Hypertension
- Hypokalemia
- Metabolic alkalosis
Symptoms of hypokalemia?
- Headaches
- palpitations
- polydipsia
- polyuria
- nocturia
Diagnostic approach to primary aldosteronism?
- 24h urine: document inappropriate K+ loss in presence of hypokalemia
- Plasma renin: suppressed
- Plasma aldosteorne: increased
- 2L N Sal –> Aldosterone fails to suppress
- High aldosterone/renin ratio
How can primary aldosteronism be localised radiologically?
- CT or MRI
- 131-iodocholesterol scanning
Treatment for primary aldosteronism?
- Adrenal adenoma = surgical excision
- Aldactone = competitive antagonist to aldosterone
- Amiloride = decrease K+ excretion by blocking Na+ channels in proximal tubule.
Phaeochromocytoma diagnosis?
- Urine catecholamines (24h)
- Plasma catecholamines
Localisation of phaeochromocytoma?
- CT
- Meta iodo benzyl guanidine scanning (MIBG)
- Octreotide scanning
- Venous sampling
What is polyglandular autoimmune syndrome type 1?
Very rare AR disorder.
Caused by mutation in AIRE gene on Chr 21.
What is MEN1?
AD condition due to defect in gene on Chr 11.
Tumours of Pituitary / Pancreas / Parathyroid
What causes MEN2?
AD condition due to mutations on RET proto oncogene on Chr 10.
Conditions associated with MEN2a?
- Medullary carcinoma of thyroid
- Phaeochromocytoma
- Parathyroid hyperplasia
