Radiation changes

Radiation changes, also radiation effect, are seen occasionally by pathologists. They are usually a result of prior (radiation) treatments. The history is important in making this diagnosis

Gross

• +/-Fibrotic appearing tissue.

Microscopic

Features:

• Cytoplasmic vacuolation - usually abundant.
• Nucleus:
  • Enlarged nucleus - but normal NC ratio.
  • No nuclear membrane irregularies.
  • Chromatin: "smudgy".
  • +/-Multinucleation.
• +/-Fibrosis (chronic change).
• +/-Edema (acute change).

Important note:

• Pleomorphism is often suggestive of malignancy. Paradoxically, in the context of radiation, less pleomorphic (clonal-appearing) cells may be malignant!

DDx:

• Pleomorphic tumours.

See also

• Radiation colitis.
• Radiation changes in cervical cytology.
• Radiation oncology.