Primary hyperparathyroidism Flashcards
What is primary hyperparathyroidism?
Primary hyperparathyroidism is caused by excess secretion of PTH resulting in hypercalcaemia. It is the most common cause of hypercalcaemia in outpatients and is often diagnosed following an incidental finding of an elevated serum calcium concentration.
What is the most common cause of primary hyperparathyroidism?
In 85% of cases, a parathyroid adenoma is responsible.
What are the causes of primary hyperparathyroidism?
85%: solitary adenoma
10%: hyperplasia
4%: multiple adenoma
1%: carcinoma
What percentage of patients with primary hyperparathyroidism are asymptomatic?
Around 80% of patients are asymptomatic and are diagnosed on routine blood tests.
What mnemonic can be used to remember the symptomatic features of primary hyperparathyroidism?
The mnemonic is: ‘bones, stones, abdominal groans and psychic moans’: polydipsia, polyuria, depression, anorexia, nausea, constipation, peptic ulceration, pancreatitis, bone pain/fracture, renal stones, hypertension.
What are some associations with primary hyperparathyroidism?
Hypertension and multiple endocrine neoplasia: MEN I and II.
What are the typical blood investigation findings in primary hyperparathyroidism?
Raised calcium, low phosphate. PTH may be raised or normal (inappropriately, given the raised calcium).
What imaging findings are associated with primary hyperparathyroidism?
Technetium-MIBI subtraction scan and x-ray findings such as pepperpot skull and osteitis fibrosa cystica.
What is the definitive treatment for primary hyperparathyroidism?
The definitive management is total parathyroidectomy.
What conservative management may be offered for primary hyperparathyroidism?
Conservative management may be offered if the calcium level is less than 0.25 mmol/L above the upper limit of normal AND the patient is > 50 years AND there is no evidence of end-organ damage.
What treatment is available for patients not suitable for surgery?
Patients not suitable for surgery may be treated with cinacalcet, a calcimimetic.
What is the action of a calcimimetic?
A calcimimetic ‘mimics’ the action of calcium on tissues by allosteric activation of the calcium-sensing receptor.
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