Question

Discuss evaluation and management of Cushing's syndrome.

Hint:

Early diagnosis and treatment of Cushing's syndrome are critical to prevent complications such as cardiovascular disease, osteoporosis, and infection.

Answer 1

Step 1: Clinical Features of Cushing's Syndrome:
Cushing's syndrome is characterized by excess cortisol in the body. Common clinical features include central obesity, moon face, buffalo hump, purple striae, hypertension, osteoporosis, muscle weakness, and easy bruising. Psychiatric symptoms such as depression, anxiety, and cognitive changes may also occur.
Step 2: Diagnostic Evaluation:
To confirm the diagnosis of Cushing’s syndrome, several tests are performed:
- 24-hour urinary free cortisol test: Elevated levels of cortisol in the urine are indicative of Cushing’s syndrome.
- Late-night salivary cortisol test: High levels of cortisol at night, when it should normally be low, suggest the presence of the syndrome.
- Dexamethasone suppression test: In patients with Cushing’s syndrome, dexamethasone (a synthetic glucocorticoid) fails to suppress cortisol production.

Step 3: Determining the Source of Excess Cortisol:
Once Cushing's syndrome is diagnosed, the next step is determining the cause:
- ACTH-dependent: This includes Cushing's disease (pituitary adenoma) and ectopic ACTH production, often by small cell lung cancer.
- ACTH-independent: This includes adrenal tumours or adrenal hyperplasia that produce excess cortisol without stimulation by ACTH.
Imaging studies such as MRI of the pituitary gland and CT scans of the adrenal glands can help identify the source of excess cortisol.
Step 4: Treatment of Cushing’s Syndrome:
The treatment depends on the underlying cause: - Surgical treatment: Removal of the pituitary adenoma in Cushing’s disease, or resection of adrenal tumours.
- Medical treatment: In cases where surgery is not possible or there is a delay in surgery, medications like ketoconazole, mitotane, or metyrapone can be used to inhibit cortisol production.
- Radiation therapy: If the tumour is inaccessible by surgery, radiation may be considered.

Step 5: Post-treatment Management:
After treatment, patients need close follow-up to monitor cortisol levels, assess for potential recurrence of the tumour, and manage any complications such as adrenal insufficiency (in cases where bilateral adrenalectomy is performed).