Adrenal Cushing's syndrome

Cushing's syndrome: caused by glucocorticoid excess
- central obesity, hypertension, moon facies, easy brusibility, weakness, depression, polyuria, glucose intolerance and diabetes

Gluccocorticoid secreting lesiosn:
- adrenal: adenomas, hyperplasia, adrenocortical carcinomas
- pituitary: adenomas, hyperplasia
- ectopic: SCLLC, bronchial carcinoid tumors, thymomas, pancreatic islet cell tumors

Diagnosis:

- elevated 24-hour urinary free cortisol most sensitive and specific test

- if 24 hour urine is negative formal low-dose dexamethasone suppression test can be performed

Important distinction during work-up:
- ACTH dependent or independent (adrenal adenoma and candidate for resection)
- measure plasma ACTH levels: should be low in ACTH independent tumors
Imaging:
- CT or MRI both can be used for localizing the tumor
- if pituitary or ectopic lesion suspected then imaging of head/chest may be warranted

Pre-op considerations:
- treat with stress-dose of steroids: taper slowly (the contralateral adrenal will be suppressed from pre-operative excess steroid secretion)
- pre-op antibiotics (due to immunosuppression from steroids)

TReatment:
- surgical resection of bilateral hyperplasia is indicated in this disease
- patient will requirer lifetime glucocorticoid and mineralocorticoid replacement (Florinef 0.1mg qD)