[Bleomycin lung (author's transl)]

Histological and electron-microscopic study of the lungs of 15 patients who had been treated with bleomycin for advanced squamous cell carcinoma demonstrated marked histological changes in nine. They were typical of bleomycin effects: alveolitis, intra-alveolar and interstitial oedema, pulmonary hyaline membranes, disseminated intravascular coagulation, intraalveolar and interstitial fibrosis, atelectasis, metaplasia and dysplasia of the alveolar lining cells. These lesions had a focal distribution, preferentially in the subpleural and periseptal regions. Each of these lesions alone is a non-characteristic reaction, but their combination makes it a distinct entity (bleomycin lung). Three different clinical courses were noted: (1) cases with no or little abnormality; (2) acute form during or shortly after bleomycin treatment; (3) chronic, progressive form of bleomycin lung which may end fatally as late as 1 1/2 years after bleomycin treatment had been discontinued. Squamous cell metaplasia is the most characteristic sign of bleomycin lung. It should not be confused with pulmonary metastases. To prove the diagnosis of bleomycin lung often requires systematic histological investigation. A schema of the pathogenesis of the bleomycin lung is proposed in which the formation of microthrombi plays an important part.