SpinThin, a simple, inexpensive technique for preparation of thin-layer cervical cytology from liquid-based specimens: data on 791 cases.

Acceptance of liquid-based fixatives for cervical cytology has been limited by the more complex slide-preparation procedures, increased cost, and reports that increased sensitivity has been based largely on comparison with conventional cytology without histologic correlation. Here the authors describe and evaluate a technically simple and relatively inexpensive method (which they call SpinThin) for preparing Cytospin (Shandon Inc., Pittsburgh, PA) cervical cytology slides from samples in liquid fixative using a modified electric toothbrush holder to put the cells in suspension. Results are compared with conventional cytology and histologic biopsy. A total of 791 cervical cytology specimens from 2 patient groups at high risk of uterine cervical neoplasia were entered into this study, and a spatula and cytobrush (174 specimens) or cytobroom (617 specimens) were used to collect conventional smears. The collection device with remaining cellular sample was placed in an alcohol-based fixative solution; the cells were put into suspension by a brief burst of vibration using a modified electric toothbrush holder, then cytocentrifuged on a slide and stained with the Papanicolaou technique. Specimen adequacy in SpinThin slides was better than that of conventional cytology smears. However, the prevalence of dysplasia, including atypical squamous cells of undetermined significance (ASCUS-D), in conventional smears and SpinThin slides was the same--27% and 25%, respectively--and excluding ASCUS-D, it was 20% in both. The prevalence of neoplasia (low or high grade squamous intraepithelial lesion, or carcinoma) histologically was 31% in the 647 cases biopsied, and agreement with histology was similar for SpinThin and conventional smears. Using a simple and relatively inexpensive new technique (Spin-Thin), slides prepared from fluid-based cervical cytology specimens obtained with the cytobrush or cytobroom correlated very well with the corresponding conventional smears within major diagnostic categories, and both correlated well with histology.