Hyperparathyroidism Diagnosis and Management
Initial Diagnostic Workup
- The Endocrine Society recommends measuring serum calcium and intact parathyroid hormone (iPTH) simultaneously for the diagnosis of hyperparathyroidism 1, 2
- Measure serum calcium (total calcium corrected for albumin) and iPTH simultaneously for accurate diagnosis 1, 2
Differential Diagnosis
- Secondary hyperparathyroidism is characterized by normal or low serum calcium with elevated PTH, often seen in chronic kidney disease, vitamin D deficiency, and malabsorption syndromes 2
- Tertiary hyperparathyroidism is characterized by hypercalcemia with elevated PTH, commonly seen in patients with end-stage renal disease 3
Imaging Studies
- Ultrasound of the neck is recommended as the first-line localization study for hyperparathyroidism 4
- Dual-phase 99mTc-sestamibi scintigraphy with SPECT/CT (parathyroid scan) is a useful imaging modality for localizing parathyroid adenomas or hyperplasia 4
- The combination of ultrasound and sestamibi scan provides the highest sensitivity for localization 4
- MRI or CT scan may be considered if initial imaging is negative 3
Management Algorithm
- Parathyroidectomy is the only definitive cure for primary hyperparathyroidism (PHPT) and is recommended for patients with severe hyperparathyroidism 4, 5
- Surgical approaches for PHPT include resection of solitary enlarged gland and total four-gland parathyroidectomy with autotransplantation 4, 5
- Cinacalcet is indicated for hypercalcemia in patients with PHPT who cannot undergo parathyroidectomy, and active vitamin D analogs (calcitriol or alfacalcidol) are recommended for secondary hyperparathyroidism in chronic kidney disease 3, 6, 7
- Phosphate restriction and phosphate binders are essential for managing secondary hyperparathyroidism in chronic kidney disease 3
Post-Parathyroidectomy Management
- Monitor ionized calcium every 4-6 hours for the first 48-72 hours after surgery to prevent hypocalcemia 3
- Initiate calcium gluconate infusion if ionized calcium falls below normal, and provide calcium carbonate and calcitriol when oral intake is possible 3
Special Considerations
- For patients with MEN syndromes, screening for PHPT with serum calcium should begin at age 11 for high-risk variants and age 16 for moderate-risk variants 4, 5
- In patients with X-linked hypophosphatemia, secondary hyperparathyroidism should be managed by increasing active vitamin D and/or decreasing phosphate supplements 7, 8
- Calcimimetics (cinacalcet) may be considered for persistent secondary hyperparathyroidism but should be used with caution due to the risk of hypocalcemia 7, 8