Abstract
Nuclear features of the cell were studied by a transmission electron microscopy in bronchial carcinoma in situ and atypical squamous metaplasia induced in dogs by means of bronchial submucous injections of 20-Methylcholanthrene.
In carcinoma in situ, many population of the cell showed an increased complexity of nuclear form and an enlargement of the nucleoli. An abundance of perichromatin granule was also seen around nuclear membrane. In atypical squamous metaplasia the cells in superficial layers showed an increased complexity of nuclear form. On the other hand, the cells in middle and basal layers revealed slightly irregular in nuclear form. Perichromatin granules were less in atypical metaplasia than these in carcinoma in situ. Enlargement of the nucleoli was also inconspicuous.
These results indicate that there are differences, although some similarities exist, between bronchial carcinoma in situ and atypical squamous metaplasia in nuclear form, number of perichromatin granules and enlargement of the nucleoli.
