ブレオマイシンの治療効果とその副作用である肺病変の病理組織学的研究

第2編 ブレオマイシン肺炎

抄録

Fourty autopsy cases of malignant tumors treated with Bleomycin were studied histopathologically on the serious side effects of the lung, and the following conclusions were obtained:
1) Pulmonary changes induced by Bleomycin treatment were observed in 29 (75.5%) among 40 autopsy cases including the case of slight changes, and Bleomycin pneumonitis showing moderate degree worthy of it's name was found in 21 cases (52.5%), and pulmonary fibrosis in 14 cases (35%). There were 15 cases (37.5%) died mainly of this pneumonitis.
2) From macroscopical findings, Bleomycin pneumonitis was classified into three types; 1) diffuse type, 2) nodular type and 3) peripheral type. Among them, the diffuse type was the cases which were treated by the largest amount of the dosage, and the nodular type was given the smallest amount.
3) Histological features of Bleomycin pneumonitis was interstitial pneumonitis involving alveoli, alveolar duct and bronchioli; at first edema appeared in alveolar walls and spaces with desquamation and bizarre change of proliferated alveolar lining cells. Hyaline membranes and large mononuclear cells were also seen in alveolar spaces. And then, these exudates and proliferated cells fell into degeneration and necrosis, and they rapidly changed into organization tissue in alveolar spaces. Finally, characteristics of this pneumonitis were the intraalveolar loose fibrosis mainly composed of reticular fibers and marked proliferation and squamous metaplasia of epithelia in many respiratory bronchioli and in allied alveolar sacs which occasionally resembled to squamous cell carcinoma.
4) Pulmonary changes induced by Bleomycin are chemical pneumonitis, i. e. Bleomycin damages directly the alveolar walls involving alveolar lining cells and bronchiolar epithelia through blood vessels, and gives rise to serous exudation and regeneration, proliferation as well as bizarre change of alveolar lining cells, leading lastly to pulmonary fibrosis. On that occasion, Bleomycin pneumonitis has a tendency to occur in the aged men over than 55-60 years old, and it was produced by a very small amout of dosage with intrapleural administration. Careful application is needed as intramuscular injection of the drug produces the pneumonitis more easy than intravenous injection.
5) Histological differentiation between Bleomycin-pneumonitis and allied interstitial pneumonitides were described.