Thyroid Disorders USMLE Step 1 Practice Question
A 56-year-old woman presents with recurrent nephrolithiasis and progressive diffuse bone pain. Vital signs: BP 138/82 mmHg, HR 88/min, RR 14/min, temperature 37.2°C. Laboratory studies reveal serum calcium 11.8 mg/dL, phosphate 2.1 mg/dL (low), intact PTH 285 pg/mL (elevated), and 24-hour urine calcium 380 mg/day (high). Renal ultrasound confirms bilateral calcium oxalate stones. She denies recent hyperthyroidism symptoms. Which of the following is the most likely diagnosis?
Answer choices
- APseudohypoparathyroidism
- BHypoparathyroidism
- CPrimary hyperparathyroidismCorrect answer
- DCalcitonin excess
- EVitamin D deficiency
- FHumoral hypercalcemia of malignancy from PTHrP secretion
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