Adequacy of cellular material in split-sampling of cervical scrapings for routine cancer screening: an analysis of 702 smears

The aim of this study was to examine cells (split-sample) that were retained on sampling devices used to collect conventional Pap smears (primary smears) in order to evaluate specimen adequacy and cytological diagnosis of scrapings that are routinely discarded. Cervical scrapings from women attending routine cervical cancer screening were obtained using a cervical brush. Following primary conventional smear preparation, the same sampling devices were rinsed in Preservcyt solution (Cytyc) for subsequent monolayered thin smear (split-sample/discarded sample). The smears (conventional and ThinPrep monolayer) were examined independently by pathologists and classified using the Bethesda System. The diagnoses from discarded samples (split-sample smears) were then compared with the diagnoses made on primary conventional Pap smears. 702 samples were studied. Cell abnormalities was found in 14/702 conventional smear and 12/702 split-sample thin smear. The adequacy of sampling in primary smears was 94.7% compared to 88.9% in split-sample smears. Six cases of Human Papillomavirus infection was found in split-sample smear, whereas only 5 cases found in primary smear. Cohen's Kappa was 0.61 showing substantial agreement between both sampling cytological results. The cervical brush discarded after conventional smear retain adequate number of cells for diagnostic purposes.