Background and Epidemiology
- Third most common endocrine disorder (prevalence of between 1 and 20 per 1000 and incidence of around 27-30 per 100,000/year)
- More common with age, post-menopausal women and with thiazide diuretic use
Aetiology
- The majority is caused by a single parathyroid adenoma (85%). Multiple adenoma / multiple parathyroid gland involve accounts for most of the remainder. Rarely can parathyroid cancer cause hyperparathyroidism (<1%)
- Inferior parathyroids more commonly involved than superior
- Ectopic glands may also cause hyperparathyroidism in up to 15% of cases (most common in the mediastinum (thymus), oesophagus, thyroid, or jaw)
- Familial cases can occur as part of multiple endocrine neoplasia syndromes (MEN 1 or MEN 2a)
Clinical Presentation
- Majority are asymptomatic (incidental diagnosis)
- Bones, stones, groans and moans
- Bone pain/pathological fractures (osteopenia)
- Renal stone disease (most common presentation)
- Groans
- Muscle weakness (proximal myopathy), fatigue
- Abdominal pain, anorexia, nausea, vomiting, constipation, dyspepsia, acute pancreatitis
- Moans
- Depression
- Difficulty concentrating, lethargy, fatigue
- Rarely presents with cardiac abnormalities e.g. hypertension, short QT interval
Investigation
see hypercalcaemia
- Investigation of renal stone disease (i.e. imaging)
- Bone imaging (DEXA)
- Parathyroid imaging (Technetium scan)
Management
- For patients with mild, asymptomatic disease, monitoring (annually) is all that is required
- Indications for removal of the parathyroids (surgery) include:
- Severe hypercalcaemia (>3mmol/l or >0.25mmol/l above the upper limit of normal); often if it requires treatment
- Renal stone disease
- Low bone density
- Other complications of hypercalcaemia
- Young patients (<50) with potentially long follow-up
- Medical treatments e.g. bisphosphonates, HRT/raloxifene +/- Cinacalcet can occasionally be used (more common in secondary hyperparathyroidism e.g. due to renal disease)
Notes on Medicine/Surgery 