Evaluation of proposed cytomorphologic criteria for the diagnosis of Chlamydia trachomatis in Papanicolaou smears.

To evaluate the proposed cytomorphologic criteria for the cervical cytologic diagnosis of Chlamydia trachomatis infection, a study was made of 171 endocervical smears. All cytomorphologic elements that could be ascribed to Chlamydia trachomatis infection were correlated with the diagnostic confirmation of this microorganism by monoclonal antibody (MAb) staining. The presence of Chlamydia trachomatis was detected in 21 samples (12.28%) by MAb staining. Comparing the cytomorphologic results with the MAb results, the sensitivities and specificities of the Papanicolaou smear diagnoses were 19% and 86% using the cytologic criteria proposed by Gupta and coworkers, 38% and 87% using the criteria proposed by Kiviat and coworkers and 23% and 91% using the criteria proposed by Shiina. In view of (1) its low sensitivity, (2) the subjective elements and individual variations in the proposed cytologic criteria, (3) the similarity with Trichomonas vaginalis-produced exudates and (4) the implications of a misdiagnosis of a sexually transmitted disease, it is concluded that cervical cytology is not useful for ascertaining the presence of Chlamydia trachomatis.