From the Guidelines
An endometrial thickness of 9mm is concerning and requires further evaluation, particularly in postmenopausal women, as it exceeds the normal cutoff of 4-5mm and raises concern for endometrial hyperplasia or cancer. In premenopausal women, this measurement may be normal depending on the menstrual cycle phase, with the endometrium typically thickest during the secretory phase 1. For postmenopausal women with this finding, endometrial sampling is recommended, usually via an endometrial biopsy in the office setting or hysteroscopy with directed biopsy if the initial sampling is inadequate or symptoms persist 1.
Some key points to consider in the evaluation of an endometrial thickness of 9mm include:
- The clinical context, such as the presence of abnormal uterine bleeding, which is a common symptom of endometrial cancer 1
- The patient's menopausal status, as postmenopausal women are at higher risk for endometrial cancer 1
- The presence of risk factors, such as obesity, diabetes, tamoxifen use, and family history of endometrial or colon cancer 1
- The use of transvaginal ultrasound to assess for other concerning features, such as heterogeneity, irregular borders, or increased vascularity 1
It is essential to note that endometrial cancer is the most common gynecologic malignancy, and abnormal endometrial thickening is often the earliest detectable sign, allowing for early intervention when the disease is most treatable 1. Therefore, prompt evaluation and management of an endometrial thickness of 9mm are crucial to reduce the risk of morbidity and mortality.
From the Research
Endometrium Measurement
- An endometrium measuring 9mm in thickness is considered significant in certain clinical contexts, particularly in postmenopausal women with vaginal bleeding 2.
- A cut-off value of 3mm is recommended for measuring endometrial thickness in symptomatic women, but the cost-effectiveness of this strategy has yet to be shown 2.
- Transvaginal ultrasound is a commonly used method for measuring endometrial thickness and can help identify women at risk of endometrial cancer 3, 4, 5.
Clinical Significance
- An endometrial thickness of 9mm may indicate an increased risk of endometrial cancer or hyperplasia, particularly in postmenopausal women 4, 2.
- However, ultrasound alone cannot reliably distinguish between benign proliferation, hyperplasia, polyps, and cancer, and tissue sampling is often required for a definitive diagnosis 3, 5.
- The American Cancer Society recommends that all women older than 65 years be informed of the risks and symptoms of endometrial cancer and advised to seek evaluation if symptoms occur 4.
Diagnostic Evaluation
- Transvaginal sonography, endometrial biopsy, and hysteroscopy are all useful diagnostic tools for evaluating the endometrium in women with abnormal uterine bleeding 3, 6, 5.
- The choice of diagnostic test depends on the individual patient's symptoms, medical history, and risk factors for endometrial cancer 4, 2, 5.
- Hysteroscopy is a valuable tool for visualizing the endometrium and performing directed biopsies, and may become the new gold standard for evaluating abnormal uterine bleeding 3, 6.