Evaluation of cellular residue in the ThinPrep® PreservCyt™ vial

The ThinPrep Pap Test™ is a fluid‐based method used for the collection and preparation of cervicovaginal samples. The collection device(s) is/are rinsed in Cytyc's ThinPrep® PreservCyt™ medium and a thin‐layer slide is prepared using the ThinPrep 2000 automated processor. The purpose of this study was to determine the detection rates for cervical lesions utilizing an additional ThinPrep slide. Fifty‐four cervical samples processed by the ThinPrep method were reviewed. An additional thin‐layer slide was obtained from the cellular residue for each case utilizing a new filter. Case selection criteria included cases with a few equivocal cells, a few diagnostic cells, or several low‐grade dysplastic cells seen on the original ThinPrep slide. The original slides and repeat slides were reviewed by two cytopathologists and two cytopathology fellows. Fifty‐four patients were included in the study, mean age 35 years (range: 16–76). The original diagnoses included: 17 negative cases, 22 atypical squamous cells of undetermined significance (ASCUS), 10 low‐grade squamous intraepithelial lesions (LGSILs), four high‐grade squamous intraepithelial lesions (HGSILs), and one case of atypical glandular cells of undetermined significance (AGUS). On the repeat slides the diagnosis remained the same in 42 (77.8%) cases, diagnostic cells were not present in 10 (18.5%) cases, fungal elements consistent with candida were detected on the repeat smear in one case (1.8%), and higher grade dysplastic cells were found in two cases (3.7%). Our study showed that the ThinPrep method provides a representative, diagnostic sample on the slide. Repeat processing adds little to the overall diagnosis. Diagn. Cytopathol. 2000;23:208–212. © 2000 Wiley‐Liss, Inc.