Pap smear adequacy--is the assessing criterion including endocervical cells really valid?

The significance of endocervical cylindrical cells (EC) as a criterion of sample adequacy has been established on 1,000 patients by comparing VCE smears (vaginal, cervical, endocervical) with or without EC in relation to prevalence of abnormal cells, prevalence of histological diagnosed lesions and sensitivity and negative predictive value of Pap smear, as well as by comparison of negative findings without EC with control smears with the aim of discovering overlooked lesions. A considerably greater yield of cytological (107/536 in relation to 49/464) and histological (105/536 in relation to 55/464) (p < 0.05) abnormalities in smears with EC support the hypothesis that the presence of EC is strongly and positively associated with prevalence of disease. In contrast, the presence of EC predicts only a moderate improvement in Pap smear quality with a weaker effect on sensitivity (95% in relation to 80%). During two-years monitoring of patients with negative Pap smear and negative colposcopy (403 with EC and 390 without EC in smears), no positive cytology/histology diagnosis was made. Also, because the prevalence of missed lesions among negative Pap smears is extremely low in absolute terms, no appreciable impact on negative predictive value was observed (98.8% in relation to 97.3%).