Cushing disease is cortisol excess caused by a pituitary tumor that makes too much ACTH, which drives the adrenal glands. It is the most common cause of Cushing syndrome that is not due to steroid medicines, and it is more common in women.
Key symptoms
- Weight gain around the trunk and face
- Easy bruising and thin skin
- Muscle weakness, mostly in the thighs and shoulders
- Mood changes, poor sleep and irregular periods
- Headache or vision changes when the tumor is large
What you find on exam
- Round face, fat pad behind the neck and central obesity
- Wide purple stretch marks on the abdomen
- High blood pressure
- Weak proximal muscles: trouble rising from a chair
- Darker skin when ACTH is very high
Tests
- Screening: late-night salivary cortisol, 24-hour urine free cortisol or 1 mg overnight dexamethasone test
- ACTH level: normal or high points to an ACTH-driven cause
- Pituitary MRI
- Inferior petrosal sinus sampling if the MRI is unclear; glucose and potassium
Treatment basics
- Transsphenoidal surgery to remove the tumor is first line
- Steroid replacement for a time after surgery while the body recovers
- Drugs if surgery fails: osilodrostat, ketoconazole, metyrapone or pasireotide
- Radiation or removal of both adrenals in resistant cases
- Treat diabetes, blood pressure, bone loss and clot risk
Red flags
- Severe low potassium with weakness or arrhythmia
- Psychosis or severe depression
- Signs of serious infection, a clot or adrenal crisis after surgery
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.