Osteoma

Bones

• Benign neoplasm of bone
• Uncommon
• In horses and cattle
• Sites
  • Flat bones (skull, scapula)
  • Mainly affect jaws and sinuses
• Grossly:
  • Smooth bordered, slow-growing tumours
• Histologically:
  • Covered with thin layer of bone
  • Consist of cancellous bone
  • Differentiated osteoblasts and osteoclasts
• Cause disfigurement, may obstruct nasal passages
• Recur if not completely removed

Paranasal Sinuses

In Horses

• Haemartoma arising from periosteum of the skull or facial bones
• See Bones and Cartilage - hyperplastic and neoplastic
• Benign
• Clinical signs:
  • Mucopurulent discharge
  • Facial distortion
  • Epiphora
  • Obstructed air flow