The idea that surface carcinoma could be the forerunner of invasive carcinoma was first conceived by Broders1and Schiller.2Several reports in the journalistic literature have proved conclusively that invasion does follow preinvasive carcinoma of the cervix uteri.3Therefore the detection and diagnosis of carcinoma of the cervix in its preinvasive phase offers a challenge to the members of the medical profession because adequate treatment of the lesion at this stage should result in cure. The study of exfoliated cells, which was initiated by Papanicolaou and Traut,4has enabled the physician to detect cancer in its subclinical stage. It is necessary, however, to confirm the diagnosis by histologic study. Multiple biopsies at the squamocolumnar junction of the cervix must be secured for two reasons: first, the site of the early carcinoma may be so small as to be missed5; second, it is necessary to differentiate