26th April 2024

A 39-year-old woman presents with a history of weight gain concentrated around the abdomen and thinning of the skin over the past year.

A 39-year-old woman presents with a history of weight gain concentrated around the abdomen and thinning of the skin over the past year. She also complains of increasing fatigue, muscle weakness, and easy bruising. She has noticed her periods becoming irregular. On examination, she has purple striae on her abdomen. Her blood pressure is 150/95 mmHg.

Investigations:

24-hour urinary free cortisol: Elevated

Plasma ACTH: Low

Serum potassium: 3.2 mmol/L (3.5-5.1)

Fasting glucose: 6.8 mmol/L (3.9-5.6)

Dexamethasone suppression test: No suppression of cortisol

Which is the most likely diagnosis?