False-negative Papanicolaou tests in women with biopsy-proven invasive endocervical adenocarcinoma/adenocarcinoma in situ: a retrospective analysis with assessment of interobserver agreement.

INTRODUCTION: The objectives of our study were to identify factors contributing to false-negative Papanicolaou (Pap) tests in patients with endocervical adenocarcinoma (EA) or adenocarcinoma in situ (AIS), and to analyze the impact of educational instruction on interobserver agreement in these cases. MATERIALS AND METHODS: False-negative Pap tests from patients with EA/AIS were reviewed by a consensus group and by 12 individual reviewers in 2 rounds, with an educational session on glandular neoplasia in Pap tests conducted between the 2 rounds. RESULTS: Of 79 Pap tests from patients with EA/AIS, 57 (72.2%) were diagnosed as abnormal and 22 (27.8%) as negative. Of the 22 false-negative cases, 10 remained negative on consensus review, with false-negative diagnoses attributed to sampling variance. The other 12 cases were upgraded to epithelial abnormalities (including 8 to glandular lesions). The false-negative diagnoses were attributed to screening variance in 2 cases and interpretive variance in 10 cases. On individual review, abnormal cells were misinterpreted as reactive glandular cells or endometrial cells in 7 of 8 and 5 of 8 cases upgraded to glandular abnormalities, respectively. With education, the proportion of individual reviewers demonstrating at least moderate agreement with the consensus diagnosis (Cohen's kappa >0.4) increased from 33% (4 of 12) to 75% (9 of 12). CONCLUSIONS: Sampling and interpretive variance each accounted for nearly one-half of the false-negative Pap tests, with underclassification as reactive glandular or endometrial cells the main source of the interpretive variances. Educational instruction significantly decreased the interpretive variance and interobserver variability in the diagnosis of glandular abnormalities.

Rescreening of high-risk HPV positive Papanicolaou tests initially screened as negative is a low yield procedure in the era of HPV genotyping.

INTRODUCTION: Many laboratories rescreen Papanicolaou test slides initially interpreted as negative, but positive for human papillomavirus (HPV) high-risk types, as a quality control measure. We have evaluated the utility of this practice in the era of HPV genotyping as a laboratory improvement project. MATERIAL AND METHODS: Between August 2016 and October 2019, we identified 3618 rescreened Papanicolaou tests with follow-up biopsies. The biopsy results were put into 3 groups: 1) Negative; 2) LSIL: HPV changes or low-grade squamous intraepithelial lesion; and 3) HSIL: high-grade squamous intraepithelial lesion or carcinoma. HPV molecular testing results with subtyping for types 16 and 18 were available for 3117 of these cases. RESULTS: A total of 530 of 2812 Papanicolaou tests (18.8%) with positive HPV results were reinterpreted as cytologically abnormal after rescreening; 75 (14.2%) had a biopsy result of HSIL. The subset positive for HPV types 16/18 had 38 of 133 cytology positive cases diagnosed as HSIL on biopsy vs. 107 of 935 cytology negative cases diagnosed as HSIL on biopsy (28.6% vs. 11.4%, P < 0.0001). The subset positive for "other" (non-16/18) high-risk HPV types had 37 of 397 cytology positive follow-up HSIL vs. 84 of 1288 cytology negative follow-up HSIL (9.3% vs. 6.5%, P = 0.075). CONCLUSIONS: Rescreening has the highest yield in specimens positive for types 16/18. However, for this group colposcopy is recommended regardless of cytology findings, reducing the patient benefit. Routine rescreening of cytology negative/HPV positive Papanicolaou tests has reduced utility when HPV subtyping is performed and should be reconsidered.