Experience with a thin-layer, liquid-based cervical cytologic screening method

OBJECTIVE: To assess the utility of a thin-layer cytology system for cervicovaginal screening in clinical practice. STUDY DESIGN: Twenty-five hundred cervicovaginal split samples were processed with the traditional direct smearing method and with the ThinPrep(R) Pap Test (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) method and evaluated according to the Bethesda system, focusing mainly on the cytomorphologic features. RESULTS: The ThinPrep(R) Pap Test yielded improved specimen adequacy and an increased detection rate of squamous abnormalities, which resulted in a decrease in the ASCUS/SIL ratio. Moreover, the thin-layer system provided adequate material for concomitant HPV testing, mainly in the LSIL and the ASCUS favor SIL cases, with satisfactory results, as well as for cell block preparations in a few selected cases that presented diagnostic difficulties. Furthermore, the morphologic features of the LSIL cases were virtually identical on both preparations, while in the HSIL cases, distinct features were noted on ThinPrep.(R) CONCLUSION: The ThinPrep(R) Pap Test is significantly more effective than the conventional smear in clinical practice. However, training and experience are necessary to take full advantage of this promising new technology.