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EXAMINATION AND INVESTIGATION OF ADRENAL DISORDER
PRESENTED BY:GROUP 9
SUPERVISED BY:DR TAN LI PING
OUTLINE
• ANATOMY (GROSS & HISTOLOGY)• PHYSIOLOGY• ADRENAL DISORDER– CAUSES– EXAMINATION– INVESTIGATION
ANATOMY: GROSS
ANATOMY: HISTOLOGY
Cortex
Medulla
Catecholamines
Androgens
Glucocorticoid
Mineralocorticoid
PHYSIOLOGY: REGULATIONZONA GLOMERULOSA(G)
ZONA FASCICULATA(F)
ZONA RETICULARIS(R)
HORMONE SECRETED
Mineralocorticoids Glucocorticoids Adrenal androgens
REGULATION / CONTROL
Renin-angiotensin-aldosterone system
Hypothalamic-pituitary axis
Hypothalamic-pituitary axis
ACTH DEPENDENT
Only for the first step in steroid biosynthesis
√ √
PHYSIOLOGY: MINERALOCORTICOIDS
↑ Na+ reabsorption
↑ K+ secretion
↑ H+ secretion
PHYSIOLOGY: GLUCOCORTICOIDS• (↑ gluconeo, proteolysis, lipolysis & ↓ glu
utilisation, insulin sensitivity)Stimulation of
gluconeogenesis
• (induces the synthesis of lipocortin which inhibit phospholipase A2, inhibit the release of histamine & serotonin from mast cells
Antiinflammatory effects
• (inhibit production of IL-2 & proliferation of T lymphocytes)
Suppression of immune response
• (up-regulating α1-adrenergic receptor in arterioles)Maintenance of vascular
responsiveness to catecholamines
• (↓ osteoblast collagen production, ↓ intestinal Ca2+ absorption)Inhibition of bone formation
• (vasoD of aferent arterioles)Increase in GFR
• (↓ REM, ↑slow-wave sleep, ↑awake time)Effect on limbic system
ADRENAL DISORDER
ADRENAL CORTEX
HYPERCUSHING’S
SYNDROME
PRIMARY
HYPERALDOS-
TERONISM
HYPO
ADDISON’S DISEASE
ADRENAL MEDULLA
PHEOCHROMO-CYTOMA
ADDISON’S DISEASE
AETIOLOGYAdrenal insufficiency
Primary
Destruction of adrenal gland
Secondary
Pituitary dysfunction
AETIOLOGY
AUTOIMMUNE (80%) TB
Metastatic tumour (lung, breast,
renal) & lymphoma
Adrenal haemorrhage (Waterhouse-Friedrichsen syndrome)
Opportunistic infection of HIV
(CMV, fungal infection)
Amyloidosis
Congenital (late-onset
CAH)
PATHOPHYSIOLOGY
Mineralocorticoid deficiency
↑ in urinary excretion of Na, ↓ in urinary excretion of K
Inability to concentrate urine, with electrolyte imbalance
severe dehydration
plasma hypertonicity, acidosis, hypotension
circulatory collapse
Glucocorticoid deficiency
Disturbances in carbohydrate, fat and protein metabolism, decrease liver glycogen
Hypoglycaemia and anorexia
Destruction of adrenal gland
Mineralocorticoid & glucocorticoid deficiency
HISTORYOften diagnosed late• Weakness, fatigue• Loss of appetite, loss of weight, anorexia• Dizziness, syncope• GI symptom: Nausea, vomiting, abdominal pain, diarrhoea,
constipation• Skin pigmentation (ask if has been sitting in the sun)• Mood: Depression, psychosis, low self-esteem• Myalgia, arthralgia• Addisonian crisis: oliguria, weak, confused, comatose,
hypoglycaemic symptoms (cold peripheries, excessive sweating, hunger, syncope)
* Think of Addison’s in all those with unexplained abdominal symptoms
EXAMINATION
• Examine for hyperpigmentation:– Hand: palmar creases– Mouth and lips– Areas usually covered by clothing: nipple– Areas irritated by belts, straps, collars or rings
• Look for vitiligo• Look for sparse axillary hair and pubic hair• Examine the abdomen for adrenal scar • Examine blood pressure for postural hypotension• DXT: hypoglycaemia• Signs of critical deterioration (Addisonian crisis):
– Shock (low BP, tachycardia)– hypothermia
INVESTIGATION: BLOOD
BUSE•Low Na •High K •Low HCO3•Azotemia
FBC•Elevated hematocrit •Low WBC count •Relative lymphocytosis •Increased eosinophils
RBS / DXT
•Hypoglycemia (< 3 mmol/L)
INVESTIGATION: IMAGING
AXR •Calcifications in the adrenal areas - PTB
CXR •Small heart
INVESTIGATION: CONFIRM DIAGNOSIS
• A single depressed plasma cortisol level in a patient who is severely stressed or in shock is highly suggestive of adrenal insufficiency
• Short ACTH stimulation test (Synacthen test):
Preinjection plasma cortisol level (N= 138 – 690 nmol/L)
IV Tetracosactide 250 µg
Plasma cortisol level at 30 – 90 minutes post injection (≥ 500 nmol/LFailure to respond → adrenal insufficiency (? Primary / secondary)
Primary (2° negative feedback)
Secondary
Plasma ACTH level
Plasma ACTH level
INVESTIGATION: DIAGNOSIS OF ADDISON’S DISEASE
Negative
Synacthen test
High plasma ACTH level
ADDISON’SDISEASE
ADDISON’S DISEASE
PHAEOCHROMOCYTOMA
INTRODUCTION
• Tumour of chromaffin cells• 80% of pheochromocytomas are found in the
adrenal medulla, usually benign• Extra-medulla tumors – 1-3% in chest and neck
(usually malignant)• 20% multiple, 10% malignant • Part of familial syndromes – MEN Type II
(Sipple’s syndrome), neurofibromatois and von Hipple-Lindau disease
SYMPTOMS AND SIGNS• Hypertension, may be paroxysmal or persistent. Due
to secretion of one or more of catecholamine hormones or precursors: norepinephrine, epinephrine, dopamine or dopa.
• Tachycardia, sweating, postural hypotension, tachypnea, flushing, cold and clammy skin, severe headache, angina, palpitation, dyspnoea
• Paroxysmal attacks may be provoked by exercise, anaesthesia, palpation of tumor, postural changes, urination, beta-blockers
DIAGNOSIS• Screening - Two 24 h urines for catecholamines is the best screening
investigation - 24 h urine for VMA (15% false negative) and metanephrine
(10% false negative) - needs vanilla-tree diet before collection
• If the diagnosis is established, or strongly suspected• MIBG scan - meta-iodo-benzylguanidine labeled with 131I - Increased uptake by pheochromocytoma
• CT scan of adrenals - patient should be alpha- and beta-blocked to avoid hypertensive episode after contrast administration