Hyperparathyroidism

Question 1

Define Hyperparathyroidism

Answer 1

Excess of parathyroid hormone (PTH) release

Primary: Autonomous overproduction of PTH which results in derangement of calcium metabolism

Secondary: elevation of PTH levels as a response to hypocalcaemia

Tertiary: Autonomous PTH secretion following chronic secondary hyperparathyroidism

Question 2

Aetiology of Primary Hyperparathyroidism

Answer 2

Inappropriate PTH secretion -> hypercalcaemia

Parathyroid adenoma (85%)
Multiple adenoma and gland hyeprtrophy 
MEN-1, MEN-2, HPTH-jaw tumour syndrome 
Lithium 
<1% parathyroid malignancy

Question 3

Aetiology of Secondary Hyperparathyroidism

Answer 3

Hypocalcaemia -> appropriate PTH elevation

Chronic Kidney Disease (loss of 1-alpha hydroxylase)
Malbsorption (Crohn’s, Coeliac, Chronic pancreatitis, gastric bypass)
Inadequate sunlight exposure (vit D deficiency)
Increased calcium/metabolic requirement (bone growth, after pregnancy, bisphosphonates, loop diuretics, rhabdomyolysis, sepsis)

Question 4

Epidemiology of Hyperparathyroidism

Answer 4

Primary hyperPTH is the most common cause of hypercalcaemia in outpatients

All dialysis-dependent chronic renal failure patients develop secondary hyperPTH

Question 5

Symptoms of Primary Hyperparathyroidism

Answer 5

Most are asymptomatic (Developed countries)

> 80% symptomatic in poor-resource nations

Psychic groans: Fatigue, anxiety, depression, poor sleep, memory loss
Abdominal moans: abdo pain, constipation, anorexia, nausea, pancreatitis, dyspepsia
Neck lump
Stones: severe loin to groin pain

Bone pain and frequent fractures (osteoporosis)
Myalgia 
Parasthaesia 
Muscle cramps
Polyuria, polydipsia

Question 6

Symptoms of Secondary Hyperparathyroidism

Answer 6

Muscle cramps and bone pain
Peri-oral tingling
Paraesthesia (hands, mouth, feet, lips)
Convulsions

Hx of fractures

Question 7

Signs of primary Hyperparathyroidism

Answer 7

Neuromuscular dysfunction
Cardiovascular dysfunction
Hard, dense neck mass

Question 8

Signs of secondary Hyperparathyroidism

Answer 8

Chvostek’s sign
Trousseau’s sign
Bowed legs/knock knees (vit D deficiency)

Question 9

Investigations for Hyperparathyroidism

Answer 9

Serum calcium, phosphate, PTH, vit D:
- Primary: ↑ calcium, ↓ phosphate, ↑ PTH
- Secondary: ↓ calcium, ↓ phosphate, ↑ PTH
- Tertiary: ↑ calcium, ↑ phosphate, ↑ PTH
Sestamibi scanning: +ve for solitary adenoma or multi-gland involvement, shows hyperplasia
USS neck: parathyroid gland hyperplasia

24h urinary calcium: high/normal (primary), low in familial hypocalciuric hypercalcaemia

Serum alk phos: may be raised

DEXA scan: Identify osteoporosis

Question 10

Management for acute hypercalcaemia

Answer 10

IV fluids, 4-6 in 24h

Question 11

Management for Primary Hyperparathyroidism

Answer 11

Parathyroidectomy
+ vit D supplements (ergocalciferol), bisphosphonates and cinacalcet

Check Ca/PTH at 2 weeks and 6 months

Question 12

Management for secondary Hyperparathyroidism

Answer 12

Treat underlying cause

Calcium + vit D supplements

Question 13

Complications of Hyperparathyroidism

Answer 13

Primary: bone resorption, renal tubular calcium reabsorption, hypercalcaemia

Secondary: bone resorption + turnover - osteitis fibrosa cystica

Question 14

Prognosis for Hyperparathyroidism

Answer 14

Primary: surgery is curative for benign disease

Secondary/tertiary: prognosis same as CKD