Objective: To determine the impact of not keeping the collecting device in liquid-based cytology. Loss of material was computed from a pair of subsamples from the same cervical scrape. One subsample was obtained by rinsing the collecting device in one vial and the other by discarding it in another vial. Homogeneity of endocervical component was assessed between subsamples.
Materials and methods: Loss of material was analyzed with a two-way analysis of variance whose two factors were G (five gynecologists) and R (number of rinsing rotations in the first vial). Endocervical clusters were counted on slides prepared from all subsamples.
Results: Globally, 37% of cellular material is lost when the collecting device is discarded. Loss of material is different among gynecologists. The more intense the rinsing process, the less the loss, but the latter is never zero and is poorly predictable. The discarded subsample often contains a greater amount of endocervical clusters.
Conclusions: Discarding collecting device in liquid-based cytology reproduces one of the flaws of the conventional smear technique. Losing cellular material may have an impact on cervical cancer detection, but this still has to be evaluated with further investigations.