A 26-year-old man presents to his primary care physician complaining of multiple episodes of easy bruising after playing basketball. He recently started playing ball again after he noticed that he was...

A 26-year-old man presents to his primary care physician complaining of multiple episodes of easy bruising after playing basketball. He recently started playing ball again after he noticed that he was growing a “beer belly” even though he hardly drank any alcohol. He also complains of little to no libido. Among other findings, the physician notes a plethoric, round face and skin atrophy, particularly over the pretibial areas. The most useful screening test for Cushing in this case is:

A. Measure plasma cortisol

B. Measure 24-hour urinary cortisol production

C. Perform a low- and high-dose dexamethasone suppression test

D. Perform a pituitary MRI

E. Perform an abdominal computed axial tomography scan