Squamous intraepithelial lesions and squamous cell carcinomas detected by endometrial sampling: Pap test correlation and outcome data.

Introduction: Squamous intraepithelial lesions (SIL) and squamous cell carcinomas (SCC) can rarely be detected in endometrial sampling. We reviewed all cases of SIL and SCC detected solely on endometrial biopsies and curettings to determine their significance and whether these findings were detected on prior or concurrent Papanicolaou (Pap) test.
Materials and Methods: Endometrial samples with detached fragments of SIL and SCC over a 13-year period were reviewed, along with prior and/or concurrent Pap tests, human papillomavirus status, and subsequent pathology results. Cases with concurrent cervical or endocervical sampling that showed SIL or SCC were excluded.
Results: Fifty patients had endometrial biopsies and/or curettings with SIL or SCC. Thirty-six patients (72%) had concurrent or previous Pap tests within 1 year prior to the endometrial sampling. The Pap test was negative for intraepithelial lesion or malignancy in 44% of patients (16/36) and atypical squamous cells of undetermined significance in 22% of patients (8/36). The source of the SIL and SCC in endometrial sampling was cervical SIL in 18 patients, cervical SCC in 14 patients, endometrioid carcinomas in 3 patients, metastatic carcinoma in 1 patient, and not definitively identified in 14 patients.
Conclusions: The majority of SIL and SCC in endometrial samples are from the cervix. Prior and concurrent Pap tests were often negative for intraepithelial lesion or malignancy in patients with SIL and SCC detected by endometrial samples. This suggests that SIL and SCC detected on endometrial sampling may detect a subset of cervical SIL/SCC that are more proximal in the endocervical canal and are not sampled with conventional Pap tests.
(Copyright © 2015 American Society of Cytopathology. Published by Elsevier Inc. All rights reserved.)