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

Abstract

RESUMOObjetivo: verifi car se, no escrutínio de rotina, fatores relacionados com a adequabilidade da amostra, padrão celular e critérios citomorfológicos estão associados a resultados falso-negativos (FN) dos exames citopatológicos. Métodos: trata-se de um estudo caso-controle, no qual o grupo de casos incluiu 100 esfregaços citopatológicos com um resultado FN que foi detectado pela sistemática de controle interno da qualidade com revisão rápida de 100%. Para cada resultado FN detectado foram identifi cados, pelo mesmo citotécnico, dois esfregaços com um diagnóstico verdadeiro-positivo e este grupo foi considerado controle, totalizando uma casuística de 300 esfregaços. As variáveis analisadas foram estabelecidas de acordo com os critérios defi nidos para a análise da adequabilidade da amostra, padrão celular e critérios citomorfológicos. Os resultados foram avaliados por análise bivariada e regressão logística com critério de seleção de variáveis stepwise e expressos em OR (95%). Resultados: o número de células atípicas, aspecto da cromatina nuclear, distribuição e apresentação de células atípicas no esfregaço apresentaram risco maior para resultados FN, com OR de 9,6; 4,2; 4,4 e 3,6, respectivamente. Processo infl amatório e presença de sangue no esfregaço mostraram também risco para os resultados FN. Conclusões: a maioria dos fatores associados à liberação de um resultado FN é dependente das condições e técnicas de coleta de material, pois, em grande parte, a lesão pode não estar adequadamente representada no esfregaço, e também fatores obscurecedores como sangue e processo infl amatório podem prejudicar a análise. Quanto às alterações citomorfológicas, cromatina fi na foi a característica que apresentou maior risco para resultados FN. PALAVRAS-CHAVE:Colo do útero/patologia; Neoplasias do colo uterino/diagnostico; Reações falso-negativas ABSTRACT Purpose: to evaluate whether factors related to the adequacy of the sample, cell pattern and cytomorphological criteria are associated with false-negative (FN) results of cervical cytopathology during routine examinations. Methods: this is a case-control study in which the study group included 100 cytopathologic smears with FN results detected during systematic internal quality control consisting of 100% rapid review. For each FN result detected, two smears with a true-positive diagnosis were identifi ed by the same cytotechnician and these constituted the control group, making a total sample size of 300 smears. The variables were established in accordance with the criteria defi ned for the analysis of sample adequacy, cell pattern and cytomorphological analyzed 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 9.6, 4.2, 4.4, and 3.6, respectively. Infl...

Improvement in the routine screening of cervical smears

“…Many but not all the abnormal smears that failed to be identified at routine screening probably contain few abnormal cells or cells with few criteria indicative of malignancy, in addition to obscuring factors. 38,43,[45][46][47] Hence, the sensitivity of rapid prescreening compared with 100% rapid review may be overestimated because the former includes both truly positive and false-negative results. Nevertheless, in the present study the sensitivity of rapid prescreening was calculated at 2 moments: when the truly positive and false-negative findings at routine screening were included in the analysis, the sensitivity of rapid prescreening was 75.6%, whereas when only the false-negatives were included in the analysis, the sensitivity of rapid prescreening was higher (90.2%), with that of 100% rapid review only 57.0%.…”

Does 100% Rapid Review Improve Cervical Cancer Screening?

“…Various methods of internal quality monitoring have been developed with the purpose of reducing errors of scrutiny and analysis of the cytology diagnosis, among them the 100% rapid review (100% RR) of negative smears [8, 10]. The 100% RR consists of quickly scrutinizing all smears considered negative.…”

Comparative study of the results from conventional cervico-vaginal oncotic cytology and liquid-based cytology

“…Although this method is widely used the limitations of cervical-vaginal cytology, which are related to its sensibility, have became evident: subjectivity, mistakes in collection and fixation (5) , large number of unsatisfactory tests, small number of cells that remain in the slide (20%) (6) and false-negative results. Perhaps, the mistakes in collection are the most important factors because they precede all others steps in the process.…”