Parathyroid

Question 1

What are the causes of primary hyperparathyroidism?

Answer 1

Adenoma.
Carcinoma.
Hyperplasia.
Familial endocrine disorders:
> multiple endocrine neoplasia.
> Jaws syndrome.
> Hypocalcuric hypercalcaemia.

Question 2

What does primary hyperparathyroidism lead to?

Answer 2

Increased PTH release > increased serum Ca2+

Question 3

What causes secondary hyperparathyroidism?

Answer 3

Hypocalcaemia > increased PTH release > parathyroid gland hyperplasia.

Question 4

What causes tertiary hyperparathyroidism?

Answer 4

Increased PTH due to prolonged secondary hyperparathyroidism > hypercalcaemia.

Question 5

What are the causes of hypoparathyroidism?

Answer 5

Parathyroidectomy. 
Radioactive iodine treatment.
Hypomagnaesaemia - inhibits PTH release.
Di George syndrome.
Pseudohypoparathyroidism.

Question 6

What will blood investigations for hypoparathyroidism show?

Answer 6

Low Ca2+
Low PTH.
Elevated phosphate

Question 7

What is pseudohypoparathyroidism?

Answer 7

PTH insensitivity.

Question 8

What will blood investigations for pseudohypoparathyroidism show?

Answer 8

Low Ca2+
Elevated PTH.
Elevated phosphate.

Question 9

What is albrights hereditary osteodystrophy?

Answer 9

Autosomal dominant disorder which causes pseudohypoparathyroidism with developmental defects.

Question 10

What are the symptoms of albrights?

Answer 10

Short stature.
Short 4th metacarpal.
Obesity.
Soft tissue calcification.
Mental retardation.

Question 11

What is Di George syndrome?

Answer 11

Deletion on chromosome 22 > malfunctioning parathyroid glands > decreased PTH.

Question 12

How does hypomagnaesaemia cause hypoparathyroidism?

Answer 12

Inhibits PTH release.