From the Guidelines
Increased endometrial thickness in postmenopausal women is a significant finding that warrants further evaluation due to its association with endometrial cancer.
Key Points
- An endometrial thickness of 4 mm or more in a postmenopausal woman is considered abnormal and requires further evaluation, as it conveys a significant risk of endometrial cancer 1.
- The negative predictive value for cancer is nearly 100% if the endometrial thickness is less than 4 mm in a postmenopausal woman 1.
- Transvaginal ultrasound (TVUS) is the first-line screening test for endometrial cancer in postmenopausal women with abnormal uterine bleeding, and it can detect endometrial thickness and other benign or malignant pathologies 1.
- If the initial TVUS and clinical evaluation are negative, repeat TVUS can be performed to reassess the endometrium, as endometrial cancers may be missed on initial imaging or endometrial sampling 1.
- Endometrial sampling is recommended for postmenopausal women with an endometrial thickness of 5 mm or more, as TVUS cannot reliably determine the etiology of endometrial thickening 1.
- Hysteroscopy with biopsy can be used as a final step in the diagnostic pathway of women with postmenopausal bleeding, as it is highly accurate and clinically useful in diagnosing endometrial cancer 1.
From the Research
Significance of Increased Endometrial Thickness
- Increased endometrial thickness in postmenopausal women is associated with an increased risk of malignancy or other pathology, such as hyperplasia or polyp 2, 3, 4, 5, 6
- A thickness of greater than 5 mm is often used as a cutoff value for further evaluation, with the risk of endometrial carcinoma and atypical endometrial hyperplasia increasing significantly above this threshold 3, 4, 6
- The optimal cutoff value of endometrial thickness for predicting endometrial malignancy in postmenopausal women with asymptomatic thickened endometrium may be 10 mm, with a sensitivity and specificity of 100% and 80%, respectively 4
Diagnostic Accuracy
- The diagnostic accuracy of transvaginal ultrasonography for detecting endometrial carcinoma and atypical endometrial hyperplasia varies depending on the threshold used, with a threshold of 3.0 to 5.9 mm resulting in a higher sensitivity but lower specificity compared to higher thresholds 6
- The pooled sensitivity and specificity of transvaginal ultrasonography for detecting endometrial carcinoma and atypical endometrial hyperplasia are 0.81 and 0.70, respectively, for a threshold of 3.0 to 5.9 mm, and 0.28 and 0.86, respectively, for a threshold of ≥14.0 mm 6
Clinical Implications
- Postmenopausal women with asymptomatic endometrial thickening should undergo further evaluation, such as hysteroscopy and biopsy, to exclude endometrial malignancy, particularly if the endometrial thickness is greater than 5 mm 2, 3, 4
- The use of a 3.0 to 5.9 mm cutoff for further endometrial evaluation may be justified due to the improved sensitivity, despite the lower specificity, in detecting endometrial carcinoma and atypical endometrial hyperplasia 6