From the Guidelines
Hyperparathyroidism indicates excessive parathyroid hormone (PTH) production, which can lead to hypercalcemia and various clinical manifestations, including bone demineralization, fractures, nephrolithiasis, and neurocognitive disorders 1.
Key Features of Hyperparathyroidism
- Primary hyperparathyroidism (PHPT) is the most common form, accounting for approximately 80% of cases, and is typically caused by a single parathyroid adenoma 1.
- Hypercalcemia is a hallmark of PHPT, resulting from the excessive production of PTH, which leads to increased calcium levels in the blood 1, 2.
- PTH measurement is crucial in the diagnosis and management of hyperparathyroidism, with different assay generations recognizing various PTH fragments, which can impact clinical decisions 2, 3.
Clinical Implications
- Surgical treatment is the only curative option for PHPT, involving the excision of the abnormally functioning parathyroid tissue, and is typically indicated even in asymptomatic patients due to the potential negative effects of long-term hypercalcemia 1.
- Imaging studies play a crucial role in localizing the affected parathyroid gland(s) to facilitate targeted surgery, but have no utility in confirming or excluding the diagnosis of PHPT 1.
- Reoperative surgery is more challenging, with lower cure rates and higher complication rates, emphasizing the importance of preoperative imaging to localize the target parathyroid lesion(s) 1.
From the Research
Definition and Forms of Hyperparathyroidism
- Hyperparathyroidism is a disease characterized by hypercalcemia with hypophosphoremia resulting from increased secretion of parathyroid hormone (PTH) 4.
- It can be divided into three forms: primary, secondary, and tertiary (secondary refractory form) 4, 5.
- Primary hyperparathyroidism is caused by an intrinsic abnormal change altering excretion of parathyroid hormone, while secondary hyperparathyroidism is caused by an extrinsic abnormal change affecting calcium homeostasis stimulating production of parathyroid hormone 5.
Clinical Presentation and Diagnosis
- Hyperparathyroidism can be asymptomatic, but it may also present with symptoms such as anorexia, asthenia, and persistent stipsis, as well as nausea, vomiting, polyuria, and dehydration in more severe cases 4.
- The diagnosis of hyperparathyroidism can be made by documenting an increased serum PTH level with an increased ionized or total calcium level in primary hyperparathyroidism, and increased serum PTH level with low or normal calcium level and an underlying renal failure or vitamin D deficiency in secondary hyperparathyroidism 6.
- Imaging evaluation, such as neck ultrasound with scintigraphy or 18F-choline PET/CT, may be useful in cases where surgery is indicated 7.
Complications and Treatment
- Hyperparathyroidism can lead to complications such as osteopenia, osteitis fibrosa cystica, and altered height and weight increases due to anorexia and dehydration 4.
- Treatment of hyperparathyroidism depends on the form and severity of the disease, and may include surgical removal of an adenoma, medical management with bisphosphonates, hormone replacement therapy, and calcimimetics, as well as treatment of the underlying cause of secondary hyperparathyroidism 5, 7.
- In cases of extremely elevated hypercalcemia, emergency treatment is required to prevent injury to the heart, central nervous system, gastrointestinal tract, and kidneys 4.