Hyperparathyroidism
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Introduction
Hyperparathyroidism affects between 0.5-0.1% of the population.
- more common in women
- commonest in the 60's
A usually slight elevation of plasma calcium is present (<3.00 mmol/L) in hyperparathyroidism, which is usually asymptomatic and picked up incidentally.
"Bones, stones, moans, groans, and psychiatric overtones."
The Case of...
Differential Diagnosis
Primary hyperparathyroidism
Parathyroid adenomas are the most common cause.
Parathyroid carcinomas are present in less than 2% of cases.
Eighty percent of primary hyperparathyroidism is caused by solitary adenoma, with 20% caused by four gland hyperplasia (MEN I or II). Less than 1% is caused by carcinoma.
Secondary hyperparathyroidism
- Chronic renal failure, secondary to phosphate retention
- phaeochromocytoma
- MEN-1 (and associated parathyroid hyperplasia)
History and Physical Exam
- history
- physical exam
History
symptoms include:
- muscle weakness
- myalgias
- arthralgias
- constipation
- polyuria
- psychiatric disorders
kidney stones and peptic ulcer disease are also common
Physical Exam
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
Primary hyperparathyroidism is manifest by increased plasma calcium and decreased phosphate.
Secondary disease is usually associated with renal failure, leading to decreased calcium and increased phosphate and compensation by the parathyroid.
Tertiary hyperparathyroidism occurs after secondary disease and a loss of regulation results in the patient becoming hypercalcemic.
Diagnostic Imaging
Sestamabi scanning can be used to identify the offending gland.
Management
Surgical exploration and removal of the enlarged gland, along with biopsy of a normal-appearing gland, is often done with parathyroid adenoma.
On occasion, an offending gland is not present in normal position. Finding it is imperative, as can be done by sestamabi scanning, CT, or MRI. The thymus is the most common location.
Sestamabi scan identifying enlarged gland allows for minimally invasive therapy.
If patients with elevated PTH are asymptomatic, most surgeons would defer surgical exploration.
avoid thiazides
Other treatments include: hydration, ambulation, , bisphosphonates
Pathophysiology
The Case of...
Additional Resources
Topic Development
created: DLP, Aug 09
authors: DLP, Aug 09
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