2. Anatomy
The weight of a normal adrenal gland is
approximately 4 g. There are two distinct
components to the gland: the inner adrenal
medulla and the outer adrenal cortex
The adrenal glands are situated near the upper
poles of the kidneys, in the retroperitoneum,
within Gerota’s capsule
3.
4. BLOOD SUPPLY
The adrenal glands are well supplied by blood
vessels. The arterial blood supply branches from
the aorta and the diaphragmatic and renal
arteries and varies considerably.
5. • A usually single large adrenal vein drains on
the right side into the vena cava and on the
left side into the renal vein.
8. • The name "glucocorticoid" is a portmanteau
(glucose + cortex + steroid)
• A less common synonym is glucocorticosteroid
9.
10. DISORDERS OF THE ADRENAL
CORTEX
Incidentaloma
Definition
An incidentaloma is an adrenal mass, detected
incidentally by imaging studies conducted for
other reasons, not known previously to have
been present or causing symptoms.
11. Incidence
The prevalence of adrenal masses in autopsy studies
ranges from 1.4% to 8.7% and increases with age.
Incidentalomas
may be detected on imaging studies in 1% of patients.
More than 75% are non-functioning adenomas but
Cushing’s adenomas, phaeochromocytomas,
metastases, adrenocortical carcinomas and Conn’s
tumours can all be found this way
12.
13. Hormonal evaluation includes:
âť– morning and midnight plasma cortisol
measurements
âť–a 1-mg overnight dexamethasone suppression test;
âť– 24-hour urinary cortisol excretion;
âť–12- or 24-hour urinary excretion of metanephrines or
plasma-free metanephrines;
âť– serum potassium, plasma aldosterone and plasma
renin activity;
âť– serum DHEAS, testosterone or 17-hydroxyestradiol
(virilising or feminising tumour
14. Cross-sectional imaging such as computed tomography
(CT) or magnetic resonance imaging (MRI) should be
performed in all patients with adrenal masses.
The likelihood of an adrenal mass being an
adrenocortical carcinoma increases with the size of the
mass (25% >4 cm).
15. • Adrenal metastases are likely in patients with
a history of cancer elsewhere and the sole
indication for biopsy of an adrenal mass is to
confirm a suspected metastasis from a distant
primary site.
16.
17. Treatment
The treatment of functional adrenal tumours is
described below.
Any non-functioning adrenal tumour greater
than 4 cm in diameter and smaller tumours that
increase in size over time should undergo
surgical resection.
18. • Non-functioning tumours smaller than 4 cm
should be followed-up after 6, 12and 24
months by imaging (MRI) and hormonal
evaluation.
• If the tumour remains non-functioning and
stable in size, surveillance can be
discontinued. Repeated frequent imaging
using ionising radiation can lead to dangerous
exposure to radiation and should be avoided
19. Primary hyperaldosteronism –
(Conn’s syndrome)
Primary hyperaldosteronism (PHA) is defined by
hypertension, as a result of hypersecretion of
aldosterone.
In PHA, plasma renin activity is suppressed.
Among patients with hypertension the incidence
of PHA is approximately 2%.
20.
21. Clinical features
Most patients are between 30 and 50 years of
age with a female predominance.
Apart from hypertension, patients complain of
non-specific symptoms: headache, muscle
weakness,cramps, neurological events, polyuria,
polydypsia and nocturia.
22.
23. Diagnosis
The key feature of the biochemical diagnosis is
the assessment of the aldosterone to plasma
renin activity ratio.
Hypokalaemia may be present
24.
25. Once the biochemical diagnosis is confirmed,
MRI or CT should be performed to distinguish
unilateral from bilateral disease.
Conn’s adenomas usually measure between 1
and 2 cm and are detected by CT with a
sensitivity of 80–90%
26. • An apparent unilateral mass could be anon-
functioning tumour in a patient with bilateral
micronodular hyperplasia.
• Selective adrenal vein catheterisation can help
before a decision on non-surgical or surgical
treatment is
27. Treatment
The first-line therapy for PHA with bilateral
hyperplasia is medical treatment with
spironolactone.
In most cases supplemental antihypertensive
medication is necessary to achieve satisfactory
control of blood pressure
29. Cushing’s syndrome
Hypersecretion of cortisol caused by endogenous
production of corticosteroids is known as
Cushing’s syndrome.
It can be either ACTH-dependent or ACTH-
independent in origin.
30. • The most common cause (85%) of ACTH-
dependent Cushing’s syndrome is Cushing’s
disease resulting from a pituitary adenoma
that secretes an excessive amount of ACTH
32. Ectopic ACTH-producing tumours (small cell lung
cancer, foregut carcinoid) and CRH-producing
tumours (medullary thyroid carcinoma,
neuroendocrine pancreatic tumour) are more
infrequent causes of ACTH-dependent Cushing’s
syndrome.
Excessive or prolonged administration of
cortisol-like drugs will produce the same clinical
picture
33. In about 15% of patients, an ACTH-independent
Cushing’s syndrome (low ACTH levels) is caused
by a unilateral adrenocortical adenoma.
Adrenocortical carcinoma and bilateral
macronodular or micronodular hyperplasia
represent rare causes of hypercortisolism
34.
35. Diagnosis
â—Źâ—Ź Morning and midnight plasma cortisol levels
are elevated, usually with loss of diurnal rhythm.
â—Źâ—Ź Dexamethasone fails to suppress 24-hour
urinary cortisol excretion.
â—Źâ—Ź Serum ACTH levels discriminate ACTH-
dependent from ACTH-independent disease
36. Elevated or normal ACTH levels provide
evidence for an ACTH-producing pituitary
tumour (85%) or ectopic ACTH production.
Therefore, in patients with elevated ACTH,
MRI of the pituitary gland must be performed.
37. • If MRI is negative and additional venous
sampling from the inferior petrosal sinus has
excluded a pituitary microadenoma, a CT scan
of the chest and abdomen is warranted to
detect an ectopic ACTH-producing tumour
38. Treatment
Medical therapy with metyrapone or
ketoconazole reduces steroid synthesis and
secretion and can be used to prepare patients
with severe hypercortisolism preoperatively or if
surgery is not possible.
ACTH-producing pituitary tumours are treated
by trans-sphenoidal resection or radiotherapy.
If an ectopic ACTH source is localised, resection
will correct hypercortisolism.
39. A unilateral adenoma is treated by adrenalectomy.
in cases of bilateral ACTH-independent disease
bilateral adrenalectomy is the primary treatment.
In patient with an ectopic ACTH-dependent
Cushing’s syndrome and an irresectable or
unlocalised primary tumour should be considered
for bilateral adrenalectomy as this controls
hormone excess.
40. Adrenal insufficiency
Primary adrenal insufficiency is caused by the
loss of function of the adrenal cortex. It was first
described by Thomas Addison in 1855. An early
diagnosis is a clinical challenge, even today.
Symptoms are only evident when about 90% of
the adrenal cortex is destroyed.
41. Secondary adrenal insufficiency is caused by a
deficiency of pituitary ACTH secretion.
Tertiary adrenal deficiency is provoked by a loss of
hypothalamic CRH secretion and is caused by
therapeutic glucocorticoid administration, brain
tumour, trauma or irradiation.
42. Acute adrenal insufficiency
Acute adrenal insufficiency usually presents as
shock in combination with fever, nausea,
vomiting, abdominal pain, hypoglycaemia and
electrolyte imbalance.
Because of intestinal symptoms and fever, the
so-called Addisonian crisis is often misdiagnosed
as an acute abdominal condition
43. Chronic adrenal insufficiency
When symptoms develop over time, patients
present with anorexia, weakness and nausea. As
a result of negative feedback, ACTH and pro-
opiomelanocortin (POMC) levels increase and
cause hyperpigmentation of the skin and oral
mucosa. Hypotension, hyponatraemia,
hyperkalaemia and hypoglycaemia are
commonly observed.
44. Treatment
If a patient displays features of adrenal
insufficiency, treatment must immediately be
commenced, before awaiting the biochemical
diagnosis. Initial blood samples can be used for
later determinations of ACTH and cortisol levels. In
addition to intravenous administration of
hydrocortisone 100 mg every 6 hours, 3 litres of
saline is given in 6 hours under careful
cardiovascular monitoring. Concomitant infections,
which are frequently present, require treatment
45. Chronic adrenal insufficiency is treated by
replacement
therapy with daily oral hydrocortisone (10
mg/m2 body surface area) and fludrocortisone
(0.1 mg). Patients must be advised about the
need to take lifelong glucocorticoid and
mineralocorticoid replacement therapy.
46. • To prevent an Addisonian crisis, patients must
be aware of the need to increase the dose in
case of illness or stress. If patients with
adrenal insufficiency are scheduled for
surgery, appropriate steroid cover must be
administrated.
