Endocrine and Metaboliccommon
A 58-year-old man is found to have a serum calcium concentration of 2.78 mmol/L (2.15–2.55) on two occasions. His phosphate is 0.72 mmol/L (0.80–1.50), creatinine is normal, and parathyroid hormone is 10.2 pmol/L (1.6–6.9). He has no medications known to increase calcium and no symptoms of malignancy. Which is the most likely diagnosis?