Radiology

The radiological changes in hyperparathyroidism are:

• classically, subperiosteal bone resorption - most often on the radial aspect of the middle phalanges of the fingers; the extent correlates well with the increased serum alkaline phosphatase
  
  
• loss of lamina dura - the thin layer of compact bone forming the sheath for the tooth socket - a late sign
  
  
• extensive bone resorption in the skull gives a stippled 'pepper pot' appearance
  
  
• cystic lesions - brown tumours - may occur elsewhere in the skeleton - appear as rounded radiolucent lesions which are trabeculated - but are less common and a late sign
  
  
• resorption of metaphyseal bone in children gives rise to crippling skeletal deformities
  
  
• there may be diffuse osteopenia