Ectopic Ossification

• Production of bone in unusual location
• Contrast with ectopic mineralisation
• Usually clinically insignificant
• Heterotopic bone
  • Spicules of bone form in the lungs of older dogs and cattle
  • Clinically insignificant
• Periarticular osteophyte
• Fibrodysplasia ossificans - usually simmetrical ossification of neck, dorsum, groin and extremities of cats
• May interfere with nervous or joint function
• Metaplastic bone does not have to be ectopic (e.g. at tendon insertions)