The effects of the Bethesda System 2014 on endometrial cell reporting and follow-up endometrial biopsies in women 45 years of age and over

Introduction: The Bethesda System (TBS) guidelines for reporting the presence of endometrial cells on Papanicolaou tests increased the reporting age from 40 (TBS 2001) to 45 (TBS 2014) years. Exfoliated endometrial cells (EMC) are usually a normal finding. Nevertheless, benign-appearing EMC occasionally correspond to endometrial hyperplasia or malignancy, especially in older, postmenopausal women. This study assesses the impact of this age cutoff change. Materials and Methods: This retrospective review compares endometrial biopsies following TBS 2001 and TBS 2014. Papanicolaou tests with EMC reported in women older than age 40 or 45 years were correlated with follow-up endometrial biopsies performed between May 25, 2014, to May 26, 2015, and May 27, 2015, to May 26, 2016, respectively. Results: The number of reported EMC declined from 770 to 492 (a 36.1% decrease). The follow-up endometrial biopsy rate for Papanicolaou tests reporting EMC using TBS 2001 was 13.6% (105 of 770) versus TBS 2014 at 13.8% (68 of 492; P = 0.92). For TBS 2001, 15% of women aged 45 and older had follow-up biopsies (65 of 434; P = 0.62). Most follow-up biopsies showed benign endometrium. In the TBS 2001 group, 1 biopsy showed malignancy and another showed complex hyperplasia with atypia. Both patients were older than 45 years. The TBS 2014 group contained 1 biopsy of malignancy and 1 with simple hyperplasia with focal atypia. Conclusions: The implementation of TBS 2014 reduced the frequency of reporting benign-appearing endometrial cells. The follow-up biopsy rate has remained essentially the same, but the total number of biopsies performed decreased, with a similar low yield of significant abnormalities.