Radiation-induced atypia. A review.

A review of radiation-induced atypia is presented. The radiation changes are divided into acute, intermediate, and late. The presence of cancer cells following irradiation is divided into persistent carcinoma, early recurrent carcinoma, and late recurrent carcinoma. The features of each group are described, supplemented by illustrations depicting the changes. The cytologic changes of radiation are discussed by correlating the light microscopic features with the electron microscopic findings in 8 cases that were studied ultrastructurally.