Osteoradionecrosis following radiotherapy for head and neck SCC.

Histology

Macroscopic 

Three irregularly shaped fragments of mandible bone, one measuring 70x40x9mm and including ramus and head and neck of mandible, a triangular fragment 50x28x8mm and an irregularly shaped fragment 8x30x10mm including two attached teeth. The edges of each fragment are focally irregular and congested.

Microscopic appearance

Sections of the 3 bone fragments show the two larger ones to be viable bone with a vascularized marrow space and vascular fibrous tissue is seen on one end of both of them.  Within the fibrous tissue, there are fragments of bone.  The smallest fragment is non-viable, consistent with being osteoradionecrosis.  There is some vascularization of marrow spaces at one end of the fragment.

Final Diagnosis

Right mandible:  Viable bone and nonviable bone, consistent with being osteoradionecrosis.  The viable bone shows revascularization.