Evaluation of the benefit and use of the new terminology in endometrial cytology reporting system

ObjectiveThe introduction and establishment of a new classification system for endometrial cytology, the “New Terminology in Endometrial Cytology (NTEMC) system,” which is based on the Bethesda System for uterine cervical cytology, has recently been reported. However, the clinical management for new categories in the NTEMC system, particularly atypical endometrial cells (ATEC), has not been clarified. The objective of the present study is to determine how the ATEC category should be treated and whether the introduction of the system has decreased the number of unnecessary endometrial biopsies.MethodsFifty‐nine cases were diagnosed as “suspicious positive” according to the three‐tier reporting (TTR) system, which was adopted in Japan. The specimens were re‐evaluated according to the NTEMC system. Thirty‐seven of the 59 patients underwent endometrial biopsy. We correlated the pathological diagnosis with the NTEMC system category.ResultsThe 59 cases were classified according to the NTEMC system as follows: 36 cases were classified as ATEC of undetermined significance (ATEC‐US), 21 cases were classified as ATEC for which atypical endometrial hyperplasia or worse cannot be excluded (ATEC‐A), and 2 cases were classified as endometrial hyperplasia. The ratio of atypical endometrial hyperplasia or malignancy in ATEC‐US category was significantly lower than that in ATEC‐A category. Fifteen cases in ATEC‐US category did not show atypical endometrial hyperplasia lesions or malignancy after 3 months.ConclusionsThese data suggest that patients with ATEC‐US results can be followed up for at least three months, and the introduction of the NTEMC system decreased the number of unnecessary endometrial biopsies.