Bronchiolitis obliterans. A new clinical-pathologic complication of irradiation pneumonitis.

A patient underwent chest irradiation for small-cell carcinoma of the left lung. Several weeks following cessation of irradiation, the patient developed hypoxemia and reticulonodular densities within the radiation port. Open lung biopsy yielded a pathologic diagnosis consistent with irradiation pneumonitis along with a previously unreported association, bronchiolitis obliterans. Bronchiolitis obliterans should be included in the pathologic description of irradiation pneumonitis.