Cytology of serous effusions: a comparative study of two slightly different preparative methods.

A prospective study of 100 serous effusions was made by two slightly different technics of smearing cells from the centrifuged sediment onto glass slides. Those made with the cotton swab had greater cell concentration and better cell morphology than matching slides prepared by the pipette-"hematologic" two-slide technic. Exclusive use of the cotton swab, therefore, is recommended in making these preparations. On follow-up, in this series of 72 patients, there was a false positive rate of zero per cent, and a false negative rate of 29%.