What is the treatment for primary hyperparathyroidism?

Treatment for Primary Hyperparathyroidism

Surgical excision of the abnormally functioning parathyroid tissue is the definitive treatment for primary hyperparathyroidism and is typically indicated even when asymptomatic, given the potential negative effects of long-term hypercalcemia. 1

Diagnostic Approach

Before treatment, diagnosis must be confirmed through:

• Biochemical testing: elevated serum calcium and non-suppressed or elevated parathyroid hormone (PTH)
• Preoperative imaging to localize the abnormal gland(s)

Surgical Management

First-line Treatment

Parathyroidectomy is the treatment of choice for primary hyperparathyroidism. Two main surgical approaches are used:

1. Minimally Invasive Parathyroidectomy (MIP):

   • Preferred for single adenomas (80% of cases)
   • Unilateral operation with limited dissection
   • Requires confident preoperative localization
   • Benefits: shorter operating times, faster recovery, decreased costs 1
   • Intraoperative PTH monitoring confirms removal of hyperfunctioning tissue

2. Bilateral Neck Exploration (BNE):

   • All parathyroid glands are identified and examined
   • Necessary when:
     • Preoperative imaging is discordant or non-localizing
     • High suspicion for multiglandular disease (15-20% of cases) 1
     • Imaging fails to identify all abnormal glands in multiglandular disease 2

Preoperative Imaging

Imaging is essential to guide surgical approach but has no role in diagnosis 1:

• Ultrasound
• 99mTc-sestamibi scintigraphy
• CT scan
• MRI
• Newer technologies: 4D-CT, PET/CT, PET/MRI for difficult cases 3

Medical Management

Medical therapy is indicated for patients who:

• Cannot undergo surgery
• Refuse surgery
• Do not meet surgical criteria 4, 5

Medical Options:

1. Cinacalcet (Calcimimetic):

   • FDA-approved for primary hyperparathyroidism in patients who meet criteria for parathyroidectomy but cannot undergo surgery 4
   • Starting dose: 30 mg twice daily
   • Titrate every 2-4 weeks through sequential doses (30 mg BID → 60 mg BID → 90 mg BID → 90 mg TID/QID) as needed
   • Monitor serum calcium within 1 week after initiation or dose adjustment 4
   • Common side effects: nausea (30%), vomiting, muscle spasms, headache 4

2. Bisphosphonates:

   • Help manage bone disease associated with hyperparathyroidism 6, 5
   • Do not significantly lower serum calcium long-term

3. Vitamin D supplementation:

   • For vitamin D deficient patients
   • Must be used cautiously to avoid worsening hypercalcemia 5

Monitoring

• For patients on medical therapy: monitor serum calcium every 2 months 4
• Regular assessment of renal function, bone density, and symptoms
• Ongoing evaluation to determine if surgical criteria develop over time 5

Special Considerations

Severe Hypercalcemia

Patients presenting with severe hypercalcemia (calcium >12 mg/dL) or hypercalcemic crisis require:

• Immediate hospitalization
• IV hydration
• Possible calcitonin for acute management
• Urgent surgical consultation 7

Multiple Endocrine Neoplasia (MEN) Syndromes

• Screen for associated conditions in suspected MEN syndromes
• In MEN 2A, screen for pheochromocytoma before parathyroid surgery 1
• More aggressive surgical approach may be needed for hereditary forms

Pitfalls to Avoid

1. Misdiagnosis: Primary hyperparathyroidism can present with vague symptoms affecting multiple organ systems and may be misdiagnosed 7

2. Relying solely on imaging for multiglandular disease: Preoperative imaging often fails to identify all abnormal glands in multiglandular disease, potentially leading to treatment failure with minimally invasive approaches 2

3. Inadequate preoperative localization: Accurate localization is essential for successful minimally invasive surgery

4. Overlooking vitamin D deficiency: Correcting vitamin D deficiency is important but must be done carefully to avoid worsening hypercalcemia

5. Delaying surgery in symptomatic patients: Medical therapy should not delay definitive surgical treatment in appropriate candidates