Bronchiolitis obliterans organizing pneumonia after adjuvant radiotherapy for breast carcinoma.

External radiotherapy following surgery for breast carcinoma may induce radiation injury to the lungs in a number of patients. Two types of injury are recognized that are temporally related to radiotherapy; an acute pneumonitis-like illness and fibrosis, with abnormalities confined to the radiation port (1). However, the spectrum of radiotherapy-induced sequelae may be more diverse. Two patients developed a syndrome of idiopathic bronchiolitis obliterans organizing pneumonia (BOOP; synonym: cryptogenic organizing pneumonitis) after surgical intervention for breast carcinoma and treatment with external radiotherapy. As a distinctive feature, the syndrome was associated with migratory, recurrent infiltrates.