Hyperparathyroidism Flashcards
Define Hyperparathyroidism
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
Aetiology of Primary Hyperparathyroidism
Inappropriate PTH secretion -> hypercalcaemia
Parathyroid adenoma (85%) Multiple adenoma and gland hyeprtrophy MEN-1, MEN-2, HPTH-jaw tumour syndrome Lithium <1% parathyroid malignancy
Aetiology of Secondary Hyperparathyroidism
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)
Epidemiology of Hyperparathyroidism
Primary hyperPTH is the most common cause of hypercalcaemia in outpatients
All dialysis-dependent chronic renal failure patients develop secondary hyperPTH
Symptoms of Primary Hyperparathyroidism
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
Symptoms of Secondary Hyperparathyroidism
Muscle cramps and bone pain
Peri-oral tingling
Paraesthesia (hands, mouth, feet, lips)
Convulsions
Hx of fractures
Signs of primary Hyperparathyroidism
Neuromuscular dysfunction
Cardiovascular dysfunction
Hard, dense neck mass
Signs of secondary Hyperparathyroidism
Chvostek’s sign
Trousseau’s sign
Bowed legs/knock knees (vit D deficiency)
Investigations for Hyperparathyroidism
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
Management for acute hypercalcaemia
IV fluids, 4-6 in 24h
Management for Primary Hyperparathyroidism
Parathyroidectomy
+ vit D supplements (ergocalciferol), bisphosphonates and cinacalcet
Check Ca/PTH at 2 weeks and 6 months
Management for secondary Hyperparathyroidism
Treat underlying cause
Calcium + vit D supplements
Complications of Hyperparathyroidism
Primary: bone resorption, renal tubular calcium reabsorption, hypercalcaemia
Secondary: bone resorption + turnover - osteitis fibrosa cystica
Prognosis for Hyperparathyroidism
Primary: surgery is curative for benign disease
Secondary/tertiary: prognosis same as CKD