Morphologic criteria associated with Trichomonas vaginalis in liquid-based cytology

To evaluate the morphologic criteria associated with Trichomonas vaginalis on Cytyc (Marlborough, Massachusetts, U.S.A.) liquid-based cytology and to compare results between 2 types of liquid-based cytology-Cytyc and SurePath (BD Diagnostics-TriPath, Burlington, Vermont, U.S.A).

Forty thousand Cytyc liquid-based cytology cases were tested between January 2005 and 2008. Among these, 80 cases (0.2%) had aT vaginalis infection without intraepithelial lesions or other associated infectious organism. The 80 ThinPrep (Cytyc) slides were reexamined, and for each case, morphologic characteristics associated with the parasite were listed. Concerning the SurePath technique, only 1 paper has been found in the literature based on 60,104 cases with 88 cases of T vaginalis (0.17%).

Among the 80 T vaginalis patients, the most frequent features associated with the infection were the presence of cannonballs (93%), perinuclear halo (90%), reactive nuclear changes (88%) and attachment of T vaginalis to squamous cells (86%). Moreover, the presence of ghost cells was significantly more frequent in SurePath than Cytyc liquid-based cytology (p = 0.00001), and the presence of neutrophils, reactive nuclear changes, dirty background and karyorrhexis and the predominance of coccobacilli were significantly more frequent in Cytyc than SurePath liquid-based cytology (p < 0.05).

On the basis of these results, we conclude that SurePath and Cytyc, which are the both commonly used liquid-based cytologic techniques, are useful and have the same efficacy in the detection of T vaginalis infection (p = 0.99).