Table 1

Brief overview of hyperparathyroidism

SyndromePrimary hyperparathyroidismSecondary hyperparathyroidism*Tertiary hyperparathyroidism
DefinitionAutonomous PTH oversecretion from abnormal parathyroid gland(s)Pathophysiological PTH oversecretion in response to a chronic stimulus that is usually extracellular hypocalcaemiaEmergence of autonomous PTH oversecretion (neoplastic transformation) from secondary parathyroid hyperplasia usually occurring in the setting of long-standing CKD and after renal transplant
Clinical manifestationsOften asymptomatic; more symptomatic† in malignant HPTMay be symptomatic†, especially in patients with longstanding chronic kidney diseaseMay be symptomatic†; often refractory to medical therapy
BiochemistryMild hypercalcaemia with elevated PTH levels; more severe findings in malignant HPTNormocalcemia or hypocalcaemia with elevated PTH levels; in patients with CKD: hyperphosphatemia, decreased 1,25-(OH)2D3Hypercalcaemia and elevated PTH levels
RadiologySingle-gland parathyroid disease (80–85%) or multigland disease (10–15%)Multigland parathyroid diseaseMultigland parathyroid disease
PathologyParathyroid adenoma (80–85%), hyperplasia (10–15%) and/or carcinoma (<1–5%)Parathyroid hyperplasiaAutonomous nodular proliferation (often adenoma, rarely carcinoma) in a background of parathyroid hyperplasia
TreatmentSurgeryGenerally medical therapy, although surgery may be indicated in some patients with chronic kidney diseaseOften surgery, given resistance to medical therapy
  • *Secondary causes of hyperparathyroidism include chronic kidney disease (most classic), vitamin D deficiency and calcium malabsorption.

  • †Signs and symptoms include bone pain, osteoporosis, kidney stones and neuropsychiatric manifestations. Additionally, patients with hyperparathyroidism due to chronic kidney disease may experience pruritus and calcification of soft tissues and vessels.

  • CKD, chronic kidney disease; HPT, hyperparathyroidism; PTH, parathyroid hormone.