Adrenal Disorders USMLE Step 1 Practice Question
A 21-year-old woman presents with a 2-year history of progressive facial hirsutism, acne, and irregular menses occurring every 45-65 days. She denies medication use and reports no recent weight changes. Vital signs are normal. On examination, she has coarse dark hair on the face, chest, and lower abdomen; acne is present on the face and upper back. Pelvic ultrasound shows normal ovaries without cysts. Laboratory studies show: Sodium: 141 mEq/L
Potassium: 4.2 mEq/L
Fasting glucose: 97 mg/dL
17-hydroxyprogesterone: 390 ng/dL (normal 20-300)
Testosterone: 91 ng/dL (normal 8-60)
Cortisol (16:00 h): 2.8 μg/dL (normal 2-8)
Prolactin: 14 ng/mL (normal <25)
LH:FSH ratio: 2.1 (normal <2.5) Urine pregnancy test is negative. Which of the following pathophysiologic mechanisms best explains this patient's clinical presentation?
Answer choices
- AIncreased intra-adrenal conversion of precursors to androgens due to 21-hydroxylase deficiencyCorrect answer
- BPrimary gonadal failure with secondary elevation of pituitary gonadotropins
- CProlactin-secreting pituitary microadenoma suppressing GnRH release
- DExogenous anabolic steroid abuse with suppressed endogenous testosterone
- EFunctional ovarian hyperandrogenism from increased ovarian LH receptor sensitivity
- FAndrogen-secreting ovarian or adrenal tumor with suppressed ACTH
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.