Hemorrhagic/traumatic bone cyst

Etiology

• Not known, bleeding in jaw with clot resorption

Clinical

• Painless swelling of mandible
• Usually teenagers

Radiology

• Radiolucency on routine examination
• Dead space in medullary bone, especially mandible
• Cavity expands between teeth roots

Histology

• Cyst wall:
  • Tenuous layer of fibrous tissue + giant osteoclastic cells
• Lumen:
  • Blood rich in bilirubin
• No epithelial lining

Management

• Surgery to initiate bleeding and stimulate healing

Picture