Calcium and Parathyroid USMLE Step 1 Practice Question
A 45-year-old man with a history of recurrent kidney stones is found on routine labs to have serum calcium 10.2 mg/dL, phosphate 2.3 mg/dL, and PTH 92 pg/mL. Additional testing shows 24-hour urine calcium 450 mg (normal <300 mg) and normal 25-OH vitamin D. Which of the following is the most likely diagnosis?
Answer choices
- AImmobilization-related hypercalcemia
- BHyperthyroidism with increased bone turnover
- CPrimary hyperparathyroidismCorrect answer
- DVitamin A intoxication
- EFamilial hypocalciuric hypercalcemia
- FTertiary hyperparathyroidism
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