Snapshot
- A 56-year-old woman presents to her primary care physician with bone pain in her hips, constipation, and anxiety. She reports increased urinary frequency, experiences night sweats, and had an unintentional 15 pound loss over the past 2 months. Laboratory testing is significant for an elevated serum calcium, alkaline phosphatase, and parathyroid hormone and decreased serum phosphate. A computerized tomography (CT) scan of her pelvis is performed.
Introduction
- Clinical definition
- a metabolic bone disorder secondary to severe hyperparathyroidism
- Background
- parathyroid hormone (PTH) plays an important role in calcium homeostasis via increasing
- RANK ligand (RANKL) expression on osteoblasts to subsequently increase osteoclast activity
- most prominent in cortical bone
- calcium reabsorption and phosphate excretion by the nephron
- 1,25-dihydroxyvitamin D synthesis by the kidneys
- RANK ligand (RANKL) expression on osteoblasts to subsequently increase osteoclast activity
- parathyroid hormone (PTH) plays an important role in calcium homeostasis via increasing
- Etiology
- parathyroid adenoma
- parathyroid carcinoma
- renal osteodystrophy
- Pathogenesis
- excessive PTH increases bone resorption and results in
- osteoporosis
- by decreasing bone mineral density
- brown tumors
- fibrous tissue deposition in areas of lost bone
- brown color is due to hemorrhage, vascularity, and hemosiderin deposition
- osteoporosis
- excessive PTH increases bone resorption and results in
- Associated findings
- “salt and pepper” appearance of the skull on radiography
- brown tumors on computerized tomography (CT) scan
Presentation
- Symptoms
- bone pain
Treatment
- Management is directed at the underlying cause of hyperparathyroidism
- e.g., parathyroidectomy in cases of malignant PTH secretion