A 50-year-old woman presents with acute right flank pain of 72 hours in duration. Her temperature is 37degC, BP-140/85 mm Hg, and pulse 85/minute. A CBC is normal. Urinalysis reveals hematuria and urine cultures are negative. Imaging studies show stones in the right renal pelvis and ureter. This patient's condition may be associated with which of the following endocrine disorders?