Studies on the distribution of abnormal cells in cytologic preparations. VI. Pressure exerted by the gynecologist during smearing.

A model system consisting of exfoliated abnormal cells and acellular viscous, mucus-like material was used to investigate the effect of the pressure exerted during smearing on the number of abnormal cells present in the preparations. Smears were made with a cotton swab applicator from left to right with parallel strokes, without overlapping smearing and without rotating the instrument of cell collection. Light and heavy pressures done during smearing procedure were recorded by the aid of an automatic scale. By means of the smearing technique, a gradual decrease in the total number of cells was recorded along the pathway of smearing. By using heavy pressure, however, cell accumulation also occurred at the end of the pathway of the last smearing strokes. Smears made with heavy pressure contained 13% more tumor cells than those made with light pressure. It is concluded that the pressure exerted by the operator during smearing may be an important parameter influencing both the number and the distribution of abnormal cells on smear preparations. These considerations may be of significance in screening programs for tumor cell detection.