A 40-year-old man comes to the office for follow-up of hypertension. He was diagnosed with mild hypertension 6 months ago and has had good control with regular exercise and weight loss. The patient feels well and takes no medications. He does not smoke and drinks a few glasses of wine per week. The patient's medical history is otherwise unremarkable. His mother has osteoporosis that is treated with oral alendronate. On examination, inspection and palpation of the neck show no masses. Laboratory results are as follows: Serum parathyroid hormone level is 814 pg/mL. Further testing shows a high 24-hour urine calcium excretion of 325 mg. DXA scan reveals normal bone mineral density. Renal ultrasound shows multiple small (

Question

A 40-year-old man comes to the office for follow-up of hypertension.  He was diagnosed with mild hypertension 6 months ago and has had good control with regular exercise and weight loss.  The patient feels well and takes no medications.  He does not smoke and drinks a few glasses of wine per week.  The patient's medical history is otherwise unremarkable.  His mother has osteoporosis that is treated with oral alendronate.  On examination, inspection and palpation of the neck show no masses.  Laboratory results are as follows:  Serum parathyroid hormone level is 814 pg/mL.  Further testing shows a high 24-hour urine calcium excretion of 325 mg.  DXA scan reveals normal bone mineral density.  Renal ultrasound shows multiple small (<5 mm) stones in both kidneys.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d818_9845_bc81_db8d67292731_MD0003_00 This patient has hypercalcemia, hypophosphatemia, and an elevated parathyroid hormone (PTH) level consistent with primary hyperparathyroidism (PHPT). PTH causes increased reabsorption of calcium from the distal tubule, but net urinary calcium excretion is increased due to excess resorption of calcium from bones. By contrast, familial hypocalciuric hypercalcemia is characterized by hypercalcemia with an elevated PTH but low urinary calcium excretion (often <100 mg/24 hr). Parathyroidectomy is recommended for patients with symptomatic hypercalcemia. It is also recommended for patients, such as this one, with complications (eg, osteoporosis, nephrocalcinosis, nephrolithiasis, impaired renal function) or at significant risk for complications (eg, serum calcium ≥1 mg/dL above normal, urinary calcium excretion >400 mg/24 hr). In addition, younger patients (age <50) such as this one are likely to have complications during their lifetime and should be offered surgery. This patient is relatively young and has nephrolithiasis (likely as a complication of PHPT); he should therefore be referred for parathyroidectomy. Parathyroid imaging (eg, sestamibi scan, ultrasonography) helps optimize the surgical approach by potentially determining the affected side and evaluating for the possibility of a minimally invasive intervention. (Choice A) Parathyroidectomy is the treatment of choice for PHPT. However, bisphosphonate therapy can be used in patients who decline surgery and have osteopenia or osteoporosis. (Choice B) Extended CT imaging would be indicated for suspected hypercalcemia of malignancy, which typically presents with severe, symptomatic hypercalcemia, low PTH, and elevated PTH-related protein. Imaging to evaluate for multiple endocrine neoplasia syndromes is recommended only if there is evidence of multiglandular hyperparathyroidism or additional endocrine tumors. (Choice D) Continued observation is appropriate in older asymptomatic patients with near-normal calcium levels and normal bone density. (Choice E) Vitamin D supplementation is not recommended in patients with PHPT who do not have overt vitamin D deficiency as it may exacerbate hypercalcemia and hypercalciuria. This patient has a normal vitamin D level. Educational objective: The most common presentation of primary hyperparathyroidism is asymptomatic hypercalcemia with an elevated parathyroid hormone level. Parathyroidectomy is recommended for patients with symptomatic hypercalcemia and those with complications (eg, nephrolithiasis) or at increased risk for complications. Younger patients (age <50) are likely to have complications during their lifetime and should be offered surgery. References: Primary hyperparathyroidism: an update. (http://www.ncbi.nlm.nih.gov/pubmed/20890202) Guidelines for the management of asymptomatic primary hyperparathyroidism: summary statement from the third international workshop. (http://www.ncbi.nlm.nih.gov/pubmed/19193908) Sestamibi (99mTc) scan as a single localization modality in primary hyperparathyroidism and factors impacting its accuracy. (http://www.ncbi.nlm.nih.gov/pubmed/20844661)

A 40-Year-Old Man Comes to the Office for Follow-Up of Hypertension