Hypercalcaemia of malignancy

Question 1

What is the most common cause of hypercalcaemia in non-hospitalized patients

Answer 1

primary hyperparathyroidism

Question 2

What is the most common cause of hypercalcaemia in hopsitalised patients

Answer 2

malignancy

Question 3

What processes can contribute to hypercalcaemia of malignancy

Answer 3

PTHrP from tumour – squamous cell lung cancer

bone metastases

myeloma – due to increased osteoclastic bone resorption

Question 4

What is the key investigation for patients with hypercalcaemia

Answer 4

measuring PTH levels

Question 5

What may someone with hypercalcaemia of malignancy present with

Answer 5

painful bones, renal stones, abdominal groans and psychic moans

corneal calcifications

shortened QT interval on ECG

hypertension

Question 6

What investigations are needed

Answer 6

ECG
PTH levels - if high most likely to be primary hyperparathyroidism

Question 7

What is initial management of hypercalcaemia of malignancy

Answer 7

rehydration with normal saline- 3/4 litres a day

bisphosphonates may be used

Question 8

What are some other management options

Answer 8

calcitonin- quicker effect than bisphosphonates

steroids in sarcoidosis

Question 9

Why should loop diuretics be used with caution

Answer 9

furosemide can be used in hypercalcaemia - particularly in those who cannot tolerate aggressive fluid rehydration

however should be used with caution as can worsen electrolyte derangement and volume depletion