A 42-year-old woman is found to have a serum calcium of 11.2 mg/dL on routine testing. PTH is 98 pg/mL (normal 15–65). 24-hour urinary calcium is 390 mg. She is asymptomatic. Which finding would make her a definitive surgical candidate according to current guidelines?
- A Serum calcium 1 mg/dL above upper normal limit
- B 24-hour urinary calcium above 350 mg
- C Age less than 50 years ✓
- D PTH above 65 pg/mL
Correct answer: C. Age less than 50 years
Explanation
Current guidelines (4th International Workshop on Asymptomatic PHPT) recommend parathyroidectomy for asymptomatic primary hyperparathyroidism in patients aged under 50 years, as they have the longest exposure time to adverse effects. Additional criteria include serum calcium more than 1 mg/dL above upper limit, T-score below −2.5 at any site, eGFR below 60, or vertebral fracture on imaging. Urinary calcium above 400 mg/day and nephrolithiasis are also criteria, but the threshold is 400 not 350 mg/day.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.