adrenal Flashcards
Hypercortisolism (Cushing syndrome)
Characterized by excess of cortisol or by any condition producing elevated glucocorticoid levels
Exogenous are a majority of causes – administration of exogenous glucocorticoids
Endogenous causes
ACTH-dependent
Pituitary adenoma (Cushing disease) – 70% are young adult women
Ectopic ACTH – 10% are lung small cell carcinoma or carcinoids
Diagnosis
of cushings
24 hour urine free cortisol concentration increased, loss of normal diurnal pattern of cortisol secretion
Dexamethasone suppression test –
Adrenal cortical neoplasms
denomas and carcinomas, mostly 30-40 year olds, mostly sporadic, associated with Li-Fraumeni syndrome(mutation of p53) and autosomal-dominant Beckwith-Wiedemann syndrome
Hyperaldosteronism – primary
Autonomous overproduction of aldosterone (glomerulosa)
Bilateral idiopathic hyperaldosteronism (most common) – nodular adrenal hyperplasia
Adrenocortical neoplasm- (35% of cases - Conn syndrome)
hyperaldosteronism- Secondary
Decreased renal perfusion, as in arterial hypovolemia – CHF, cirrhosis, nephrotic syndrome, pregnancy
Results in activation of renin-angiotensin system, leading to increased levels of plasma renin
Clinical course – HTN, hypokalemia(K gets excreted)
Diagnosis and treatment
Primary
High aldosterone and low renin concentration
Adenomas, hyperplasia, surgical excision for medical treatment
Secondary
High aldosterone and renin concentration
Adrenogenital syndromes
Disorders of sexual differentiation such and virilization and feminization caused by primary adrenal disorders
Under the control of ACTH, adrenals produce androgens
Adrenal causes of androgenital syndrome – adrenocortical neoplasms, congenital adrenal hyperplasia
Congenital adrenal hyperplasia (CAH)
Autosomal-recessive, inherited metabolic disorder
Deficiency or lack of particular enzyme, steroid 21-hydroxylase,involved in biosynthesis of cortical steroids; also overproduction of androgens
Primary hypoadrenalism
primary adrenal disease
Loss of adrenal cortex – congenital, autoimmune, infection
2 patterns – acute (adrenal crisis) and chronic (Addison disease)
Acute (adrenal crisis)
Due to increased demand for steroids precipitated by stress in individuals with chronic adrenocortical insufficiency or in patients maintained on exogenous corticosteroids
Massive adrenal hemorrhage – overwhelming bacterial infection (Neisseria meningitidis)
Chronic (Addison disease)
Uncommon disorder due to progressive destruction of adrenal cortex – symptoms appear when at least 90% cortex is destroyed
Secondary hypoadrenalism
decreased stimulation of adrenals due to a deficiency of ACTH
Disease or suppression of hypothalamus or pituitary
Adrenal medulla
Composed of specialized NC cells (chromaffin cells) and their supporting cells
Major source of body catecholamines (80% epi, 20% NorE)
Most important disease is neoplastic – pheochromocytoma, neuroblastoma
Pheochromocytoma
Catecholamine-producing neoplasm composed of chromaffin cells
90% are benign
Have been associated with “rule of 10s”
10% are extra-adrenal
10% of sporadic adrenal pheochromocytomas are bilateral
10% of are biologically malignant
10% are not associated with HTN
Insulinoma
Most common, generally benign, most are solitary
Clinical picture of hyperinsulinism – 80% of islet cell tumors demonstrate excessive insulin secretion, 20% have clinically significant hypoglycemia
Lab findings – high circulating levels of insulin, high insulin-to-glucagon ratio
Treatment – surgical removal
Zollinger Ellison (ZE) syndrome
y hypersecretion of gastric acid and severe peptic ulceration
Peptic ulcers – present in 90-95% of patients, can be multiple, unresponsive to therapy and at unusual locations (intractable jejunal ulcers)
Usual origins in gastrinomas
Multiple endocrine neoplasia (MEN)
group of genetically inherited diseases resulting in proliferative lesions (hyperplasia, adenomas, carcinomas) of multiple endocrine organs
