Pituitary Disorders USMLE Step 1 Practice Question
A 51-year-old man presents with decreased libido and erectile dysfunction. Vital signs reveal BP 128/76 mmHg, HR 72 bpm, RR 14/min, temperature 37°C, and SpO2 98% on room air. Laboratory studies demonstrate testosterone 180 ng/dL (normal 300-1000), elevated LH 24 mIU/mL (normal 1.5-9), and elevated FSH 32 mIU/mL (normal 1.5-12). Testicular ultrasound confirms small, atrophic testes bilaterally. Prolactin levels are normal. Which of the following is the most likely diagnosis?
Answer choices
- AHyperprolactinemia
- BHypothyroidism
- CAndrogen insensitivity syndrome
- DCentral hypogonadism from pituitary insufficiency
- EPrimary hypogonadismCorrect answer
- FSecondary hypogonadism from chronic opioid use
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