Comparison of cancer cell surfaces of the lower reproductive tract by scanning electron microscopy.

The squamous cells of the cervix simulate those of the vagina and vulva both histologically and by scanning electron microscopy. However, in areas of the cervix undergoing active metaplasia, there are cells which share some of the characteristics demonstrated by scanning electron microscopy of both squamous and columnar epithelium. In these cells there is a wide range of characteristics of each cell type, suggesting a possible gradual transition from columnar to squamous epithelium. Furthermore, the cells of severe dysplasia and of intraepithelial and invasive squamous cancers of the cervix, though histologically similar to those of vaginal and vulvar cancers, are distinctly different when examined by scanning electron microscopy. These findings suggest that both metaplastic and neoplastic squamous cells are derived from the same progenitor columnar cells of the cervix, by orderly transition in the former and by atypical transformation in the latter. Second, the distinctiveness from the vaginal and vulvar cells indicates different embryonic stem cell lines.