Pero Vaz de Caminha: an-interchange program for quality control between Brazil and Portugal

To start an interexchange program for quality control in cervical cytology and discuss conceptual criteria for diagnosis.

Slides were selected in the archives of the 2 institutes and included cases with unsatisfactory, negative and positive results. Sets of slides were changed between the partners every 3 months. At the end of each year a senior cytopathologist was invited to discuss the major discrepancies found in the study.

A total of 1,041 cases were analyzed. Full concordance was obtained in 74.4% (774) of cases and discrepancies in 25.6% (267 cases). Full agreement was achieved in 276 (39%) of 707 cases categorized as negative. In 421 negative cases from laboratory A, this concordance represents 65.5% and 96.5% for laboratory B, which submitted 286 negative cases. The main discordance was the high number of atypical squamous cells of undetermined significance cases: 3.1% for A and 128 (33.2%) for B. Samples with discrepancies related to the quality of the material was another controversial issue: of 16 cases from laboratory A, 6 (37.5%) unsatisfactory cases were the same and 10 (62.5%) different. Laboratory B presented 20 unsatisfactory cases, and 14 (70.0%) had other diagnoses. Low grade squamous intraepithelial lesion and high grade squamous intraepithelial lesion concordance ranged from 75% to 80%, and invasive carcinoma has 4 discordances (28.5%), 3 previously screened as high grade squamous intraepithelial lesion and 1 as atypical squamous cells of undetermined significance. The kappa value obtained was 0.65, indicating substantial agreement.

Our results indicated that atypical squamous cells of undetermined significance diagnoses are the crucial point of controversies and concern the quality of routine diagnosis in cytopathology.