Pituitary Disorders USMLE Step 1 Practice Question
A 45-year-old man presents with progressive frontal headaches, bitemporal hemianopsia, and erectile dysfunction for 3 months. Vital signs: BP 138/88 mmHg, HR 76/min, RR 14/min, Temp 37°C, SpO2 98% on room air. Laboratory studies show elevated prolactin (125 ng/mL), normal TSH (2.1 mIU/L), and low testosterone (185 ng/dL). MRI reveals a 1.8-cm sellar mass with suprasellar extension compressing the optic chiasm. Visual acuity is preserved. Which diagnosis is most likely?
Answer choices
- AProlactinomaCorrect answer
- BACTH-secreting adenoma
- CGrowth hormone-secreting adenoma
- DNon-functioning pituitary adenoma
- ETSH-secreting adenoma
- FCraniopharyngioma causing stalk-effect hyperprolactinemia
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