Approach to the Patient: Normocalcemic Primary Hyperparathyroidism

Area of Science:

• Endocrinology
• Metabolic Bone Disease

Background:

• Normocalcemic primary hyperparathyroidism (NPHPT) is a distinct subtype of primary hyperparathyroidism.
• Characterized by elevated parathyroid hormone with normal serum calcium levels.
• Diagnosis requires exclusion of secondary hyperparathyroidism causes.

Purpose of the Study:

• To review the current understanding of NPHPT.
• To highlight diagnostic challenges and inconclusive natural history.
• To discuss the variability in skeletal and renal complications and treatment approaches.

Main Methods:

• Literature review of studies on NPHPT.
• Analysis of diagnostic criteria and exclusion of secondary causes.
• Evaluation of reported skeletal and renal outcomes and treatment efficacies.

Main Results:

• NPHPT diagnosis is challenging, often requiring exclusion of secondary causes.
• Natural history and complication severity (skeletal, renal) show variability due to selection bias.
• Surgical management via parathyroidectomy is complicated by negative localization and multiglandular disease.

Conclusions:

• Limited data hinders consensus on optimal medical and surgical treatment for NPHPT.
• Postoperative outcomes for bone mineral density and nephrolithiasis are inconsistent.
• Further high-quality studies are needed to guide evidence-based management of NPHPT.