A modification of The Bethesda System classification of cytologic findings of uterine cervix named Zagreb 1990 has been accepted in Croatia as a unique classification, the use of which has begun after the publication and printing of the new, uniform method of cytologic examination.
Aim: The aim of this study was to assess the number and type of cytologic abnormalities of uterine cervix classified according to Zagreb 1990, on routinely examined Pap smears during the 6-year period, and to investigate the connection of these abnormalities with lower genital tract infections.
Material and methods: The retrospective study included Pap smears from the City of Zagreb and from the town of Imotski. A total of 59901 Pap smears (patients aged 17-79) were routinely examined: the cytopathologic diagnosis of CIN I or higher recorded in 3664 (6.12%) of them. The control group consisted of 401 Pap smears of age-matched women referred by the same gynecologists and free from cytologic abnormalities. The most frequently diagnosed epithelial change was CIN 1 (84.57% of all epithelial changes, and 5.17% of total study population), followed by CIN II (10.92%; 0.67%), CIN III (3.11%; 0.19%), and invasive squamous carcinoma (1.31%; 0.08%). Endocervical adenocarcinoma was cytologically diagnosed in only 0.0055% of all Pap smears examined. Inflammation was significantly more common in the group with epithelial dysplasia/carcinoma than in the control group (p < 0.01). Of specific causative agents HPV and Chlamydia trachomatis were significantly more frequently found in the group with epithelial dysplasia/carcinoma than in the control group (p < 0.05 both), however, Gardnerella vaginalis, Trichomonas vaginalis or Candida yielded no significant differences. It is concluded that inflammation very likely contributes to the development of precancerous lesions of the cervix, HPV and Chlamydia showing strongest correlation, at least in a part of our population.