Cellular debris on negative liquid-based cytology cervicovaginal smears

To determine the prevalence of cellular debris (CD) on benign cervicovaginal liquid-based cytology (LBC) smears and which factors predict the presence and larger amount of CD.

Cervicovaginal smears evaluated as negative for intraepithelial lesion or malignancy (NILM) between 1 January and 31 March 2020 were retrospectively reviewed to record the presence and amount of CD. All smears were prepared with the SurePath platform. Patient ages and past medical and surgical histories were also retrieved. Multivariate regression analyses were performed to find positive predictors of a larger amount of CD.

Three hundred forty-nine NILM smears were included in this study. The cohort consisted of 222 cervical smears (CS), and 127 vaginal smears (VS) taken from patients who had undergone hysterectomy. Overall, CD was observed in 111 (31.8%) cases. The positive predictors of CD were increasing age, specimen type (VS compared to CS), history of chemotherapy or radiation therapy (CRT), and more than mild background inflammation. Among the VS group, CD was present in 64 cases (50.4%) regardless of the time between the hysterectomy and specimen collection. Positive predictors in the VS group were age and more than mild inflammation. By contrast, the prevalence of CD in the CS group was 21.2%, and age was the only positive predictor. Histories of CRT, conisation, and inflammation were not statistically significant positive predictors for CD among CS.

Cellular debris could be seen in as much as 50% of NILM smears taken after hysterectomy, regardless of the time since the procedure. Increasing age was a positive predictor of the presence and a larger quantity of CD. These findings are helpful when evaluating smears with moderate to abundant debris in the background with questionable cellular atypia.