From the Guidelines
Perimenopausal endometrial thickening should be evaluated with transvaginal ultrasound (TVUS) to measure endometrial thickness, and endometrial biopsy is recommended if the thickness exceeds 5mm or if the patient has abnormal uterine bleeding. According to the most recent and highest quality study 1, TVUS is the first-line screening test for endometrial cancer in postmenopausal women, and an endometrial thickness of 4 mm conveys a negative predictive value for cancer of nearly 100%. However, in premenopausal women, normal endometrial thickness varies with the phase of the menstrual cycle, and there is no validated absolute upper limit cutoff for endometrial thickness.
Key considerations in evaluating perimenopausal endometrial thickening include:
- Measuring endometrial thickness using TVUS, which can detect benign endometrial or myometrial pathologies such as endometrial hyperplasia, polyps, adenomyosis, or leiomyomas 1
- Combining TVUS with transabdominal US to fully assess the pelvic structures 1
- Using endometrial biopsy to evaluate the etiology of endometrial thickening, particularly in postmenopausal women with a thickened endometrium (≥5 mm) 1
- Considering saline infusion sonohysterography (SIS) or hysteroscopy to evaluate focal lesions 1
- Managing asymptomatic findings with normal histology with observation, simple hyperplasia without atypia with hormonal therapy, and complex hyperplasia or atypia with surgical intervention
It is essential to note that perimenopausal women have fluctuating estrogen levels without consistent progesterone opposition, which increases the risk of endometrial hyperplasia and potentially endometrial cancer. Therefore, regular follow-up with repeat TVUS at 3-6 month intervals is recommended for women managed conservatively. The diagnostic strategy should be tailored to each patient's individual needs, taking into account their symptoms, medical history, and risk factors for endometrial cancer 1.
From the Research
Perimenopausal Endometrial Thickening Evaluation
- The evaluation of perimenopausal endometrial thickening is crucial for the early detection of endometrial cancer 2.
- Transvaginal ultrasound (TVUS) is an accurate and non-invasive technique for investigating endometrial thickness (ET) in the early diagnosis of endometrial cancer (EC) 2.
- There is no consensus on the cutoff value for normal ET in postmenopause for either symptomatic or asymptomatic women 2, 3.
Threshold Values for Endometrial Thickness
- A threshold of ≥10 mm for ET has been suggested to prompt investigations for endometrial atypical hyperplasia and cancer in postmenopausal women without bleeding 3.
- For postmenopausal women with postmenopausal bleeding (PMB), a threshold of <4 mm for ET may be used to determine the need for further investigation 2, 4.
- A study found that an ET threshold of 11 mm yields a similar separation as ≤4 mm in those with PMB 3.
Management of Asymptomatic Postmenopausal Women
- Asymptomatic postmenopausal women with an incidental finding of a thickened endometrium (ET ≥ 5 mm) may be managed conservatively, with no need for routine endometrial sampling 5.
- However, women with ET ≥ 10 mm may require further investigation, including endometrial biopsy or hysteroscopy-guided endometrial sampling 3, 6.
Clinical Practice Guidelines
- Clinical practice guidelines recommend that postmenopausal women with asymptomatic endometrial thickening be evaluated on a case-by-case basis, taking into account individual risk factors for endometrial cancer 6.
- The use of TVUS and ET measurements should be guided by clinical judgment and individual patient risk factors, rather than relying solely on threshold values 2, 6.