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What does the adrenal gland consist of?
- Cortex
- Medulla
What are the layers of the adrenal cortex?
- Zona glomerulosa
- Zona fasciculata
- Zona reticularis
Zona glomerulosa produce?
Mineralocorticoids
- aldosterone
Zona fasciculata produce?
Glucocorticoids
- cortisol
Zona reticularis produce?
Sex steroids
- androgens
Adrenal medulla is comprised of? what do they produce?
Chromaffine cells
- synthesize and secrete catecholamines
Which three syndromes can adrenocortical hyperfunction cause?
- Conn syndrome - excess of aldosterone
- Cushings syndrome - excess of cortisol
- Congenital adrenal hyperplasia - excess of androgens
What is Conn syndrome?
Same as primary hyperaldesteronism
- Condition which occurs due to increased production of aldosterone in the adrenal cortex
Most important causes of Conn syndrome?
- Idiopathic bilateral hyperplasia
- Aldosterone-producing adrenal adenoma
- Aldosterone-producing adrenal carcinoma
Clinical features of Conn syndrome?
- Secondary hypertension
- Hypokalaemia
- Metabolic alkalosis
Why isnt Conn syndrome associated with significant oedema?
Because of the aldosterone escape mechanism
What is Cushing's syndrome?
Condition caused by excessive amounts of gluococorticoids
- especially cortisol
What are the different subtypes of Cushings syndrome?
- Pituitary Cushing syndrome
- Adrenal Cushing syndrome
- Ectopic Cushing syndrome
- Iatrogenic Cushing syndrome
What is another name of Pituitary Cushing syndrome?
Cushings disease
Cushings disease is caused by?
Caused by ACTH-producing (corticotroph) microadenomas in the anterior pituitary
- large amount of ACTH stimulates bilateral hyperplasia of the adrenal cortex
= increased production of glucocorticoids
Adrenal Cushing syndrome is caused by?
- Adrenocortical adenomas
- Adrenocortical carcinomas
Ectopic Cushing syndrome is caused by?
Occurs as a paraneoplastic syndrome, where tumors produce ACTH
- most commonly in case of small cell lung carcinoma
Iatrogenic Cushing syndrome is caused by?
Caused by prolonged glucocorticoid therapy
Morphology of the adrenal gland in Cushings syndrome?
Depend on the cause of the hypercortisolism
- cortical atrophy
- diffuse hyperplasia
- macro/micro-nodular hyperplasia
- adenoma/carcinoma
What will cause cortical atrophy?
Iatrogenic Cushing syndrome
What will cause diffuse hyperplasia?
Cushings disease
Clinical features of Cushings syndrome?
- Secondary hypertension
- Secondary diabetes
- Central obesity, thin extremities
- Buffalo hump
- Moon face
- Hyperpigmentation (in those types where ACTH is elevated)
Why is hyperpigmentation a symptom of Cushings syndrome?
Due to melanocyte-stimulating hormone
- which is a byproduct of ACTH synthesis
-> only in those types where ACTH is elevated = Cushings disease
What is congenital adrenal hyperplasia?
Group of autosomal recessive conditions
- characterized by defects in enzymes that are responsible for cortisol, aldosterone and androgen synthesis
What is the most common subtype of congenital adrenal hyperplasia?
Deficiency of 21-hydroxylase
What will deficiency of 21-hydroxylase result in?
Cause aldosterone and cortisol levels to decrease, while increasing levels of androgens
- due to decreased negative feedback
Increased levels of androgens will cause? in females
- Clitoris hypertrophy
- Early puberty
- Virilization = appearance of male characteristics, like deep voice and facial hair
Increased levels of androgens will cause? in males
Early puberty
What is adrenal insufficiency?
Condition where there is decreased production of all adrenocortical hormones
- can be primary or secondary
Primary adrenal insufficiency?
= Addison disease
- adrenal cortex itself is damaged
Addison disease can be caused by?
- Autoimmune adrenalitis
- Tuberculosis
- Sarcoidosis
- Infiltration
- Congenital adrenal hyperplasia
- Waterhouse-Friderichsen syndrome
Autoimmune adrenalitis?
Most common cause of Addisons disease
- involves an autoimmune destruction of the steroid-producing cells of the adrenal cortex
What is Waterhouse-Friderichsen syndrome?
Life-threatening condition characterized by acute adrenal insufficiency
- due to haemorrhagic necrosis of the adrenal glands
What will happen in Waterhouse-Friderichsen syndrome?
Patients will develop;
- hypotension
- circulatory shock
- death
Cause Of Waterhouse-Friderichsen Syndrome?
Most frequently develops during meningococcal (Neisseria meningitidis) sepsis
What can cause hypopituitarism?
- Non-functional anterior pituitary tumor
- Pituitary apoplexy
What is secondary adrenal insufficiency?
Condition where there is adrenal insufficiency, due to the decreased levels of ACTH
= Hypopituitarism
Tumors of the adrenal gland?
- Adrenal adenoma
- Adrenal carcinoma
- Phaeochromocytoma
- Peripheral neuroblastic tumors
What are adrenal adenomas?
Small, yellow, soft benign tumors in the adrenal glands
- most are non-functional (not hormone-secreting)
What are adrenal carcinomas?
Larger, aggressive malignant tumors in the adrenal gland
- usually contain necrosis and haemorrhage
- tend to invade adrenal veins and inferior vena cava
What are pheochromocytomas?
Benign or malignant tumors of the adrenal medulla, which originates form catecholamine-producing chromaffin cells
- can produce catecholamines
When are pheochromocytomas considered malignant?
If they are locally aggressive or metastatic
Which "rule" does pheochromocytomas follow?
10 percent rule
10 percent rule?
- 10% occur bilaterally
- 10% are familiar
- 10% are malignant
- 10% are extra-adrenal
- 10% occur in children
Pheochromocytoma can lead to?
Episodes of paroxysmal hypertensive crises
- characterized by throbbing headache, sweating, palpitations and anxiety
Complications of paroxysmal hypertensive crises?
- Apoplexy
- Rupture of aneurysms
- Myocardial infarct
- Aortic dissection
Diagnosis of pheochromocytoma?
Based on the presence of high levels of catecholamines, and catecholamine breakdown products (VMA, HVA) in a 24-hour urine sample
Peripheral neuroblastic tumors?
Tumors developing from neural crest cells, that would develop into sympathetic nervous system
- neuroblastoma
- ganglioneuroblastoma
- ganglioneuroma
