Hyperparathyroidism

Question 1

Define primary hyperparathyroidism

Answer 1

increased secretion of PTH unrelated to plasma calcium concentration

Question 2

Define secondary hyperparathyroidism

Answer 2

increased secretion of PTH secondary to hypocalcaemia

Question 3

Define tertiary hyperparathyroidism

Answer 3

autonomous PTH secretion following chronic secondary hyperparathyroidism

Question 4

Causes of primary hyperparathyroidism

4

Answer 4

Parathyroid adenoma
Parathyroid hyperplasia
Parathyroid carcinoma
MEN syndrome

Question 5

Causes of secondary hyperparathyroidism

2

Answer 5

Chronic renal failure

Vitamin D deficiency

Question 6

Epidemiology of hyperparathyroidism

incidence, gender, age

Answer 6

Primary has incidences of 5/100,000
2x as common in FEMALES
Peak incidence 40-60 yrs old

Question 7

Presenting symptoms & signs of primary hyperparathyroidism

general + 9 hypercalcaemia

Answer 7

many patients have mild hypercalcaemia & may be asymptomatic

Polyuria
Polydipsia
Renal calculi
Bone pain
Abdo pain
Nausea
Constipation
Psychological depression 
Lethargy

Question 8

Presenting symptoms & signs of secondary hyperparathyroidism

Answer 8

may present w/ signs/symptoms of hypocalcaemia or of the underlying cause (e.g. renal failure, vitamin D deficiency)

Question 9

Investigations for hyperparathyroidism

8

Answer 9

U&Es
Serum calcium 
high in primary & tertiary, low/normal in secondary
Serum phosphate
low in primary & tertiary, high in secondary
Albumin
ALP
Vitamin D
PTH
Renal US - can visualise renal calculi

Question 10

Findings in primary hyperparathyroidism

5

Answer 10

Hyperchloraemic acidosis
Normal anion gap
Due to PTH inhibition of renal reabsorption of bicarbonates
Urine - high PTH in presence of high calcium can also be caused by familial hypocalciuric hypercalcaemia (FHH)
Calcium: creatinine clearance ratio can help differentiate between primary hyperparathyroidism & FHH

Question 11

Management of hyperparathyroidism

3 groups

Answer 11

Acute hypercalcaemia
Surgical management
Secondary hyperparathyroidism management

Question 12

Management of hyperparathyroidism - acute hypercalcaemia

4

Answer 12

IV fluids
Avoid factors that exacerbate hypercalcaemia (E.g. thiazide diuretics)
Maintain adequate hydration
Moderate calcium & vitamin D intake

Question 13

Management of hyperparathyroidism - surgical

2

Answer 13

Subtotal parathyroidectomy

Total parathyroidectomy

Question 14

Management of hyperparathyroidism - 2º hyperparathyroidism

2

Answer 14

Treat underlying cause (e.g. renal failure

Calcium & vitamin D supplements may be needed

Question 15

Complications of hyperparathyroidism

3 groups

Answer 15

Primary
Secondary
Surgery

Question 16

Complications of hyperparathyroidism - primary

4

Answer 16

Increased bone resorption
Increased tubular calcium reabsorption
Increased 1α-hydroxylation of vitamin D
All lead to hypercalcaemia

Question 17

Complications of hyperparathyroidism - secondary

2

Answer 17

Increased stimulation of osteoclast & increased bone turnover
Leads to osteitis fibrosa cystica

Question 18

Complications of hyperparathyroidism - surgery

2

Answer 18

Hypocalcaemia

Recurrent laryngeal nerve palsy

Question 19

Prognosis of hyperparathyroidism

2

Answer 19

Primary - surgery is curative for benign disease in most cases
Secondary or tertiary - same prognosis as chronic renal failure