Hyperfunction of adrenal glands Flashcards
what is a common endocrine cause of hypertension?
Primary hyperaldosteronism
unilateral adenoma
bilateral hyperplasia
what are rarer ednocrine causes of hypertension?
Phaeochromcytoma
Cushing’s syndrome
Acromegaly
Hyperparathyroidism
Hypothyroidism
Congenital Adrenal hyperplasia
what syndromes cause hypersecretion from the adrenal cortex?
Cushing’s syndrome (cortisol, androgens) (adenoma, carcinoma or bilateral hyperplasia)
Conn’s syndrome (aldosterone) (adenoma or bilateral hyperplasia)
what syndromes cause hypersecretion from the adrenal medulla?
Phaeochromocytoma (catecholamines)
what is cushings syndrome?
excess corticosteroids
what type of hormone is cortisol?
catabolic hormone
what effects does cortisol have on the body?
Tissue breakdown
causes weakness of skin, muscle & bone
Sodium retention
may cause hypertension & heart failure
Insulin antagonism
may cause diabetes mellitus
what are side effects of glucocorticoid therapy?
what are common characteristic features of cushings syndrome?
what percentage of cases of cushings syndrome ACTH dependent?
75% cases:
Pituitary tumour (Cushing’s disease)
5% cases:
Ectopic ACTH secretion (eg lung carcinoid)
what percentage of cases of cushings syndrome ACTH independent?
20% cases:
Adrenal tumour (adenoma or carcinoma)
Corticosteroid therapy (eg for asthma, IBD)
describe the physiology of secondary hypersecretion due to a hypothalamic problem?
describe the physiology of secondary hypersecretion due to a pituitary problem?
describe the physiology of primary hypersecretion due to a problem with the adrenal cortex?
what approach should be taken to diagmose hypercortisolism?
what screening tests are done for cushings syndrome?
24 hr Urinary free cortisol:
normal 14- 135 nmol/24h
1mg overnight Dexamethasone suppression test taken at midnight
normal <50nmol/l (1.8 mg/dL) at 09.00h
describe ACTH levels in the morning versus the evening in a normal patient?
describe ACTH levels in the morning versus the evening in a patient with ectopic ACTH, adrenal cushings and pituitary ACTH?
High dose dexamethasone test would show what in ectopic ACTH, pituitary dependent syndrome?
what is treatment of choice to remove a pituitary tumour?
surgery
what are medical treatments available for treatment of a pituitary tumour?
Adrenal hormone synthesis inhibitors
Ketoconazole
Metyrapone
Aminoglutethimide
Etomidate
Destroy Adrenocortical cells
Mitotane
what are alternative treatment options for a pituitary tumour?
Radiotherapy
Bilateral Adrenalectomy
breifly describe the renin-angiotensin-aldosterone system?
describe the pathophysiology of primary hyperaldosteronism?
how is primary hyperaldosteronism screened for?
describethe screening tests for hyperaldosteronism?
40-year-old woman
hypertension
hypokalaemia, K+ 2.7 mmol/l (N, 3.5-5)
plasma aldosterone 1135 pmol/l (N, 100-500)
plasma renin 1.8 (N, 2.8-4.5)
Diagnosis: primary hyperaldosteronism
How would she be managed?
conns syndrome
CT scan: 2cm left adrenal mass
iodocholesterol scan: increased uptake on the left
surgical removal of benign adenoma (mostly laparoscopically now)
post-op BP 120/80
no hypotensive drugs required
