Significance of Atypical Endometrial Cells in Women Younger than 40 Years of Age

Abstract Background The presence of atypical endometrial cells (AEM) in the Papanicolaou test (Pap) has been associated with increased rate of endometrial malignancy with reported rates ranging from 14-47%. However, most studies published in the literature focused on patients who were older than 40 years. The purpose of this study was to investigate the clinical significance of identifying the atypical endometrial cells in Pap test samples in women less than 40 years of age. Design A search of the cytology Pap test database was performed from 2000 to 2014 using the keywords “atypical endometrial cells” or “atypical glandular cells favor endometrial origin” in women younger than 40 years. Available ThinPrep® slides were reviewed. Patients’ clinical presentation, follow-up endometrial biopsy, treatment, and clinical follow-ups were recorded. Endometrial carcinoma tissue sections were screened for Lynch syndrome. Results The database search yielded 63 study cases. Fifty-two patients had subsequent endometrial biopsy. Nine (17.3%) of 52 patients with follow-up biopsy had premalignant (atypical hyperplasia =5) or malignant lesions (endometrioid adenocarcinoma =4). Sixteen (30.8%) patients had other endometrial pathology. These nine patients with premalignant or malignant endometrial lesions (8 white, 1 black) were overweight or obese; three of them did not have any clinical symptoms. All four patients with endometrioid adenocarcinoma had negative Lynch syndrome screening. Conclusions Our study suggests that it is important to recognize the presence of atypical endometrial cells in Pap tests in young patients, given its association with the finding of premalignant and malignant pathology in the subsequent endometrial biopsies.