Bones, Calcium and Parathyroid Gland

Question 1

What are the 2 main causes of hypercalcaemia?

Answer 1

Primary hyperparathyroidism

Malignancy

Question 2

What are other causes of hypercalcaemia?

Answer 2

Tertiary hyperparathyroidism
Drugs (excess vit D, thiazides)
Granulomatous diseases (sarcoidosis, TB)
Familial hypercalciuric hypercalcaemia
High calcium turnover (bedridden, thyrotoxicosis, Paget's)

Question 3

What biochemistry test results would be found in primary hyperparathyroidism?

Answer 3

↑PTH (or inappropriately normal)
↑Ca2+
↑urine calcium excretion
Vit D should be replete

Question 4

What biochemistry test results would be found in hypercalcaemia caused by malignancy?

Answer 4

↑Ca2+
↑ALP
↓PTH

Question 5

What are the signs + symptoms of hypercalcaemia?

Answer 5

Bones (bone pain, fractures, bony lesions)
Stones (kidney stones)
GI moans (constipation, peptic ulcers)
Psychic moans (depression, hallucination, confusion, stupor, memory loss)
Muscle weakness, slow or absent relfexes

Question 6

What are the signs + symptoms of acute hypercalcaemia?

Answer 6

Thirst
Dehydration
Confusion
Polyuria

Question 7

What are the signs + symptoms of chronic hypercalcaemia?

Answer 7

Myopathy
Fractures
Osteopenia
Depression
Hypertension
Pancreatitis
Ulcers
Renal calculi
Calcium-induced nephrogenic diabetes insipidus

Question 8

How can hypercalcaemia be investigated?

Answer 8

Measure calcium, PTH, vit D, ALP
Urine - hypercalciuria
Imaging
ECG

Question 9

What is the acute treatment for hypercalcaemia?

Answer 9

1. Fluids
2. Loop diuretics
3. Glucocorticoids
4. Bisphosphates
5. Chemotherapy

Question 10

What causes hypocalcaemia?

Answer 10

Hypoparathyroidism
Osteomalacia
CKD
Vit D deficiency
Acute pancreatitis
Over-hydration
Respiratory alkalosis
Acute rhabdomyolysis

Question 11

What are the signs + symptoms of hypocalcaemia?(SPAMODIC)

Answer 11

Spasms
Paraesthesia
Anxious
Seizures
Muscles (cramps, weakness, ↑tone, tetany)
Orientation impaired and confusion
Dermatitis
Impetigo herptiformis
Chvostek's signs

Question 12

What complications can hypocalcaemia cause?

Answer 12

QT segment prolongation (can lead to cardiac arrest)

Cataract formation

Question 13

What is the treatment for acute hypocalcaemia?

Answer 13

Calcium gluconate (10mls of 10% over 10mins IV)

Question 14

What is the pathogenesis of primary hyperparathyroidism?

Answer 14

Primary overactivity of the parathyroid gland

Question 15

What is the most common cause of primary hyperparathyroidism?

Answer 15

Small parathyroid adenomas

Question 16

What are the other causes of primary hyperparathyroidism?

Answer 16

Parathyroid hyperplasia
MEN1 (parathyroid hyperplasia, adenoma)
MEN2 (parathyroid hyperplasia)

Question 17

What is the treatment/management of primary hyperparathyroidism?

Answer 17

Parathyroidectomy

Cinacalcet (if unfit for surgery and needs treatment)

Question 18

What is cincalcet?

Answer 18

Calcium mimetic, reduces PTH secretion

Question 19

What is the pathogenesis for secondary hyperparathyroidism?

Answer 19

Chronic hypocalcaemia causes compensatory over activity of the parathyroid glands

Question 20

What are the causes of secondary hyperparathyroidism?

Answer 20

Vitamin D deficiency

CKD

Question 21

What biochemistry test results would be seen in secondary hyperparathyroidism?

Answer 21

↓ (or normal) Ca2+

↑PTH

Question 22

What is the treatment/management of secondary hyperparathyroidism?

Answer 22

Treatment of underlying cause (vitamin D, cinacalcet)

Question 23

What is the pathogenesis of tertiary hyperparathyroidism?

Answer 23

Parathyroid hyperplasia
When secondary hyperparathyroidism is treated but the parathyroid gland is used to producing lots of PTH so continues to do so

Question 24

What biochemistry test results would be seen in tertiary hyperparathyroidism?

Answer 24

↑Ca2+ (hypercalcaemia occurs as PTH is secreted unlimitedly by feedback control)
↑↑PTH

Question 25

What is the treatment/management of tertiary hyperparathyroidism?

Answer 25

Removal of some of the hyperplasia

Question 26

What is the pathogenesis of malignant hyperparathyroidism?

Answer 26

Parathyroid-related protein (PTHrP) is produced by some squamous cell lung cancer, breast and renal cell carcinoma causing an increase in Ca2+

Question 27

What biochemistry test results would be seen in malignant hyperparathyroidism?

Answer 27

↑Ca2+ | ↓PTH

Question 28

What scan can be done to localise parathyroid adenoma?

Answer 28

Sestamibi scan

Question 29

What are the complications of hyperparathyroidism?

Answer 29

Bone disease Kidney stones GI groans (constipation, nausea, peptic ulcer, pancreatitis, gall stones) Depression, lethargy, seizures Muscular weakness and fatigue Calcification of aortic and mitral valves

Question 30

What are the primary causes of hypoparathyroidism?

Answer 30

Autoimmune Idiopathic Congenital deficiency (DiGeorge syndrome) Familial

Question 31

What are the secondary causes of hypoparathyroidism?

Answer 31

Destruction of the parathyroid gland (removal or damage during thyroidectomy, radiotherapy, malignancy) Hypomagnesaemia

Question 32

What are the causes of hypomagnesaemia?

Answer 32

``` Alcohol Drugs (thiazide diuretics, PPIs) GI illness Pancreatitis Malabsorption ```

Question 33

What is the pathogenesis for pseudohypoparathyroidism?

Answer 33

Genetic defect causes failure of target cells to respond to PTH as the PTH receptors doesn't work

Question 34

What are the signs + symptoms of pseudohypoparathyroidism?

Answer 34

``` Bone abnormalities Obesity Subcutaneous calcification Learning disabilities Brachydactyly (short 4th and 5th metacarpals) Calcified basal ganglia in brain Short stature ```

Question 35

What is pseudopseudohypoparathyroidism?

Answer 35

Morphological features of pseudohypoparathyroidism but with normal biochemistry

Question 36

What biochesmistry results are seen in pseudohypoparathyroidism?

Answer 36

↓Ca2+ | ↑PTH (due to PTH resistance), ↑phosphate

Question 37

What biochesmistry results are seen in hypoparathyroidism?

Answer 37

↓Ca2+ ↓PTH ↑phosphate

Question 38

What are the complications of hypoparathyroidism?

Answer 38

Prolonged QT interval in ECG (arrhythmias) Dental abnormalities Cataracts

Question 39

What is the treatment/management for hypoparathyroidism?

Answer 39

``` Vitamin D (alphacalcidol, cholecalciferol, calcitriol) Calcium ```