Radiation Necrosis : Pathology

Comments:
Pathophysiology: Osteoradionecrosis is a late complication of ionizing radiation. The radiated bone becomes hypovascular and hypoxic, predisposing it to avascular necrosis. The patients may develop soft tissue necrosis with exposed intraoral mandibular bone, osteomyelitis (actinomycosis) leading to tooth loss, pathologic fracture, and cutaneous fistulae.

Pathology: Radiation damage to vessels leads to necrosis of bone (shown here) followed by a chronic inflammatory phase. Eventually, there is dense hyalinization and fibrosis of the bone marrow. There may be bone remodeling associated with irregular, heavy cement lines resembling those seen in Paget disease of bone. Additional findings may include secondary osteomyelitis and reactive hyperplasia of the overlying squamous mucosa.

Image courtesy of: Dr. Ibrahim Zardawi; used with permission.