Endometrial Thickness as a Predictor of Endometrial Malignancy in Postmenopausal Bleeding

Abstract

Introduction: Postmenopausal bleeding is a common gynecologic presentation, and endometrial thickness measured by transvaginal ultrasound guides biopsy decisions. However, threshold values vary.
Methods: This review followed PRISMA guidelines. Databases searched included Embase and Web of Science. Studies evaluating endometrial thickness cutoffs (3–5 mm) against histopathological diagnosis were included. Sensitivity, specificity, and diagnostic odds ratios were pooled.
Results: Twenty-two diagnostic accuracy studies (n=8,450) were analyzed. A 4 mm threshold yielded sensitivity 0.91 and specificity 0.48 for detecting endometrial cancer. Lowering to 3 mm increased sensitivity to 0.96 but decreased specificity to 0.32. Abnormal histology was rare below 3 mm (0.4%).
Discussion: The trade-off between sensitivity and false positives is clinically important. Most guidelines use 4 mm, but the review suggests that 3 mm may be justified in high-risk populations (obesity, diabetes). Operator variability and hormonal therapy use affect thickness measurements.
Conclusions: A 4 mm endometrial thickness cutoff balances diagnostic performance for postmenopausal bleeding, but a 3 mm threshold reduces missed cancers in high-risk women. Individualized thresholds should be considered.