Fatores associados a resultados falso-negativos de exames citopatologicos do colo uterino

Abstract

Purpose: To evaluate whether factors related to the adequacy of the sample, cell pattern and cytomorphological criteria are associated with false-negative results of cervical cytopathology during routine examinations. Methods: This is a case-control study in which the study group included 100 cytopathologic smears with a false-negative (FN) result detected during systematic internal quality control consisting of 100% rapid review. For each FN result detected, two smears with a true positive (TP) diagnosis were identified by the same cytotechnician and these constituted the control group, making a total sample size of 300 smears. The variables analyzed were established in accordance with the criteria defined for the analysis of sample adequacy, cell pattern and cytomorphological criteria. The results were evaluated using bivariate analysis and logistic regression with stepwise variable selection criteria expressed in OR (95%). Results: The number of atypical cells, the appearance of nuclear chromatin, and the distribution and presentation of atypical cells in the smear were the variables that showed the greatest risk for FN results with OR of 9.

Results of a control quality strategy in cervical cytology

“…The greater the positive likelihood, the better the diagnostic test will be, so that our results allow establishing a better performance of review proposed as to screening. Nevertheless, little can be done in the laboratory in terms of reducing the FN results when the uterine cervix is not adequately represented (5) . In this sense, we are limited by the fact that the samples were collected by medical students and Gynecology residents with different degrees of experience.…”

“…There is a considerable variation (5 to 70%) in false-negative (FN) rates for the test (4) . Limitations in its sensitivity are attributed, in general, to care in patient preparation and techniques for collection of specimens (5) . Additionally, the existence of numerable cases with cytomorphological alterations with imprecise diagnostic resolution (6) and interobserver variability (7) are factors that interfere in the analytical phase of the test.…”

“…On the other hand, interpretation by different observers of borderline deviations between minor and major gravity may cause discrepancy due to the subjectivity of its qualitative and quantitative aspects (5) . When there is a high-grade squamous intraepithelial lesion (HGSIL), specific detection is of vital importance to impede its progression to invasive carcinoma (8) .…”