Two types of cells in the normal, atypical and carcinomatous squamous epithelium of the cervix. I. Light microscopic and autoradiographic study in mice.

The occurrence of two morphologically distinct cell types in the cervical epithelium of mice is reported. One of the two cell types had a large nucleus with a limited amount of cytoplasm. Cells with these characteristics were called cells with "lucid nuclei." Such cells were found in film-coated autoradiographic specimens that had been fixed in Carnoy's solution; they were readily observed by altering the quality of the light illuminating the preparations. Micrometric determinations confirmed that cells with "lucid nuclei" were larger than cells with "nonlucid nuclei." Both cell types were demonstrated to synthesize DNA and RNA precursors. The proportion of cells with "lucid nuclei" was increased in 3.4-benzopyrene-induced atypias; the highest values were reached in squamous invasive carcinoma. The causes of the significant increase in cells with "lucid nuclei" during cervical carcinogenesis in the mouse are unclear.