Final answer:
A 22-year-old woman presenting symptoms indicative of Cushing's syndrome would most likely be expected to have hypertension as an additional abnormality.
Step-by-step explanation:
Considering the likely diagnosis of Cushing's syndrome indicated by the moon-shaped facies, purple striae, central obesity, hirsutism, acne, and history of amenorrhea, an additional expected abnormality would be hypertension. Cushing's syndrome, often caused by a pituitary tumor leading to the hypersecretion of the glucocorticoid hormone cortisol, contributes to a wide range of symptoms including high blood pressure, diabetes, excessive body hair, osteoporosis, and depression. Among the listed options, hypertension is the most consistent with the signs and symptoms of Cushing's syndrome.