LATE BCNU LUNG - A LIGHT AND ULTRASTRUCTURAL-STUDY ON THE DELAYED-EFFECT OF BCNU ON THE LUNG PARENCHYMA

We describe eight patients who developed interstitial pulmonary fibrosis following BCNU (carmustine) therapy for cerebral tumours. The fibrosis presented 12-17 (mean 14) years after exposure to the drug. A distinctive pattern of pulmonary fibrosis with involvement of the apices and subpleural areas was seen in one patient dying of the disease. Light microscopy showed interstitial elastosis and intra-alveolar fibrosis which was often focal with an associated mild lymphoplasmacytic infiltrate, intra-alveolar oedema, macrophages, and some neutrophils. Ultrastructural studies showed electron lucency of type I pneumocytes, with breaks in the cytoplasmic membranes leaving a bare basement membrane. Degenerative change was also seen in endothelial cell cytoplasm along with lipofuscin deposition. While BCNU pulmonary fibrosis has been described up to 2 years after treatment, this complication so late after therapy, though rare, has important implications for the follow-up of patients receiving this drug.