Hyperparathyroidism

Tumor biology and incidence

• Characterized by elevated serum PTH, hypercalcemia and hypophosphatemia
• Classified as primary, secondary or tertiary.
  • Primary: Caused by parathyroid adenoma (approximately 80% of cases), multiple adenomas, hyperplasia or carcinoma of parathyroid tissues
  • Secondary: Usually result of renal or intestinal losses of calcium
  • Tertiary: Occurs when secondary hyperparathyroidism becomes autonomous

Presentation and physical findings

• Signs and symptoms: "Stones , bones, gastrointestinal groans, psychiatric moans, and fatigue overtones"
  • Stones: Nephrolithiasis and nephrocalcinosis
  • Bones: Often painful, tender, weak, and susceptible to pathologic fracture
  • Patient may develop generalized osteitis fibrosa cystica (fibrous replacement of the marrow) or may develop a brown tumor
  • Gastrointestinal: Abdominal pain possibly due to peptic ulcer or pancreatitis
  • Psychiatric: May develop depression, psychosis
  • Fatigue: Weakness or hypotonia of the muscles
• Elevated serum calcium, elevated serum PTH, and decreased serum phosphate

Radiographic appearance

• Early, generalized osteopenia; often overlooked
  • Changes related to increased osteoclast activity, decreased thickness of trabeculae
  • Best seen in X-rays of hands, spine
  • May see soft tissue calcification, vascular calcifications
• Moderate osteopenia: Cortical resorption canals, subperiosteal resorption of bone and, loss of the terminal cortex of tufts of phalanges
• Severe osteopenia: Advanced cortical resorption canals, subperiosteal resorption of bone.

Pathology

• May observe brown tumor of hyperparathyroidism
  • Contain abundance of giant cells in a mononuclear stroma
  • Histologically indistinguishable from giant cell tumors; diagnosis based on combination of clinical, radiologic, and pathologic data

Diagnosis and treatment

• Correct life-threatening electrolyte disturbances
• Identify and treat cause of increased PTH levels