adrenal disorder

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