Normocalcemic Hyperparathyroidism: A Heterogeneous Disorder Often Misdiagnosed?

Area of Science:

• Endocrinology
• Metabolic Bone Disease

Background:

• Normocalcemic primary hyperparathyroidism (NHPT) has been recognized for over a decade, yet its definition, prevalence, and complication rates remain unclear.
• Lack of consensus management guidelines for NHPT hinders clinical practice.
• The pathophysiology of NHPT is likely heterogeneous, with multiple contributing factors rather than a single cause.

Purpose of the Study:

• To review recent advancements in understanding the pathophysiology, evaluation, and management of NHPT.
• To address clinical concerns regarding surgical treatment for NHPT, especially when complications are present at diagnosis.
• To highlight unresolved questions about NHPT's significance and natural history.

Main Methods:

• Review of existing literature, including population-based cohorts and referral center studies.
• Analysis of diagnostic criteria and potential selection biases in reported NHPT cases.
• Examination of reported bone and renal complications in relation to laboratory findings.

Main Results:

• Heterogeneity in reported complication rates may stem from a lack of rigorous diagnostic criteria and selection bias.
• The natural history of NHPT is not fully elucidated, with some cases potentially resolving spontaneously.
• Mild laboratory alterations in NHPT may not always correlate with significant bone or kidney complications.

Conclusions:

• Caution is advised when considering surgical intervention for NHPT.
• Further research is needed to clarify the definition, pathophysiology, and long-term implications of NHPT.
• Distinguishing NHPT from secondary hyperparathyroidism is crucial for appropriate management.