Abstract
Bronchiolitis obliterans organizing pneumonia (BOOP) is a rare complication during/after irradiation following breast-conserving surgery. Similar interstitial pneumonias caused by endocrine therapy have also been reported. Herein, we present two breast cancer patients who developed BOOP during/after radiotherapy that was diagnosed as drug-induced pneumonia by the drug lymphocyte stimulation test (DLST). Case 1 was a 42 year-old female (T1cN0M0 StageI) who underwent breast-conserving surgery and radiotherapy. She developed fever and dyspnea while receiving hormonal therapy (tamoxifen). We diagnosed BOOP caused by irradiation, though DLST for tamoxifen was positive. We finally diagnosed drug-induced pneumonia. Case 2 was a 60 year-old female (T1cN0M0 StageI) who underwent breast-conserving surgery and then developed a fever, caugh and dyspnea. Twelve days after receiving radiotherapy and hormonal therapy (anastrozole) she was diagnosed with drug-induced pneumonia based on a positive DLST for anastrozole. Predonisolone was very effective in both cases. In conclusion, DLST facilitates examination for the differential diagnosis of drug-induced pneumonia in breast cancer patients with BOOP during adjuvant therapy.
