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1. C U S H I N G
D I S E A S E
B Y :
P A L A K K H A N N A
S A D H A N A S H U K L A
M A D I H A B A N O R E H A M A N I

2. A 54-year-old man complains of weight gain over 6
months, gradual loss of muscle strength, arterial
hypertension, reddish stretch marks around thighs,
patient's blood pressure 176/115 mmHg, blood
potassium levels within normal range,
adrenocorticotropic hormone (ACTH) - 2400 pg/ml
(normal range – 20-100 pg/ml), cortisol in 24-hour urine
732 mg/24 hours (normal range 15-55), aldosterone and
renin levels in the blood are within normal range, as
well as the rate of vanilmandelic acid (VMA) in the urine
is within the normal range.

3. What is the probable
diagnosis?
• Cushing disease is a condition in which the pituitary
gland releases too much adrenocorticotropic hormone
(ACTH).
• The most common cause of excess cortisol is excess
ACTH as a result of a pituitary tumour. The condition is then
termed Cushing’s disease, a subtype of Cushing’s
syndrome and the most common cause of excess
endogenous cortisol.
• Other types of endogenous Cushing’s syndrome are
those that result from adrenal disorders (eg, benign or
malignant tumours, hyperplasia) or ectopic ACTH.
• In cases of ectopic ACTH, neuroendocrine tumours (eg,
bronchial carcinoid tumour and small cell lung carcinoma)
produce ACTH outside the control of the pituitary.
• In this subtype, the ACTH levels are much more elevated
than those resulting from pituitary tumour.

5. PATHOPHYSIOLOGY

6. S Y M P T O M S

7. DIAGNOSIS
• History collection
• Physical examination
• Dexamethasone suppression test.
• MRI and CT
• Radio-immuno Assay of plasma ACTH
• Corticotropin releasing factor
(CRF) stimulation test.
• Blood sample.
• Bilateral inferior petrosal sinus
sampling (BIPSS) is a minimally
invasive procedure performed in the
workup of adrenocorticotropic hormone
(ACTH)-dependent Cushing syndrome
(CS).

9. D I F F E R E N T I A L
D I A G N O S I S :

10. MANAGEMENT
• In endogenous Cushing’s syndrome, the goals of therapy are to
reverse the clinical manifestations of the syndrome by:
• Reducing cortisol secretion to normal;
• Eradicating any tumours that impair health;
• Surgery
• Pituitary tumours can be removed with transsphenoidal surgery and this
is usually the mainstay of treatment.
• Corticosteroid replacement is usually required after adrenalectomy.
• Radiotherapy
• Pituitary radiotherapy can be used where surgery is contraindicated or
fails to reduce cortisol levels.
• Chemotherapy
• In cases of ectopic ACTH production (eg, in small cell lung cancer or
carcinoid tumour) cytotoxic agents are used if tumours cannot be
surgically removed.

11. • Cortisol-inhibiting drugs
• In particular, high circulating levels of cortisol in Cushing’s syndrome makes
patients more susceptible to infections and poor wound healing which, inevitably,
will affect post-operative recovery. Excess cortisol also impacts on peri-operative
management due to effects on, for example, blood pressure and blood glucose.
These agents can, therefore, be used to reduce cortisol levels before surgery
both to reduce morbidity and prevent complications.
• Metyrapone
• Metyrapone is a competitive inhibitor of 11β-hydroxylation. It inhibits the
conversion of pregnenolone to cortisol in the adrenal cortex. It should be
administered with food at an initial oral dose of 250mg three to four times daily.
• Side effects include hypotension, allergic skin reactions, hypoadrenalism and
hirsutism. Metyrapone can also cause drowsiness and patients should be warned
about the effect on performance of skilled tasks (eg, driving).
• Ketoconazole
• Ketoconazole inhibits 11β- hydroxylase and so the final conversion of
pregnenolone to cortisol. In addition, it inhibits 17-hydroxylase and 18-
hydroxylase activity as well as sex steroid production. It is particularly useful in
female patients with hirsutism but it can cause unacceptable gynaecomastia and
reduced libido in male patients.