Evaluation of Postmenopausal Bleeding with Thickened Endometrium
Endometrial biopsy (EMB) is the recommended evaluation for a patient with postmenopausal bleeding (PMB) and thickened endometrium due to the high risk of endometrial cancer. 1
Diagnostic Algorithm for PMB with Thickened Endometrium
Initial Assessment
- Transvaginal ultrasound (TVUS) is the first-line screening test for endometrial cancer in patients with PMB 1
- Endometrial thickness >4mm in a postmenopausal woman requires endometrial sampling due to increased risk of endometrial cancer 1
- Office endometrial biopsy is the standard diagnostic procedure for tissue sampling 2
Endometrial Biopsy Procedure
- Office endometrial biopsy using Pipelle or Vabra devices has a sensitivity of 97-99.6% for detecting endometrial cancer 1
- The histologic information from the endometrial biopsy should be sufficient for planning definitive treatment 2
- Pre-procedure medications can help manage pain/discomfort during the procedure
Follow-up After Negative Biopsy
- Office endometrial biopsies have a false-negative rate of about 10% 2
- A negative endometrial biopsy in a symptomatic patient must be followed by a fractional dilation and curettage (D&C) under anesthesia 2
- Hysteroscopy may be helpful in evaluating the endometrium for lesions such as polyps if the patient has persistent or recurrent undiagnosed bleeding 2
Clinical Considerations
Risk Factors That Increase Concern
- Postmenopausal bleeding is present in 90% of endometrial cancer cases 1
- Additional risk factors include:
- Obesity
- Diabetes mellitus
- Hypertension
- History of unopposed estrogen exposure
- Tamoxifen therapy 1
Special Imaging Considerations
- If the endometrium cannot be completely evaluated by ultrasound, endometrial sampling should still be performed based on the patient's risk factors 2
- MRI can be considered if ultrasound visualization is inadequate due to patient factors or uterine pathology 2
- Even with a thin endometrium (<4mm), persistent bleeding requires further evaluation 1
Pitfalls and Caveats
- Endometrial biopsy may not be accurate for diagnosing malignancies of the uterine wall such as mesenchymal tumors 2
- Hysteroscopy alone has poor validity for excluding endometrial hyperplasia and cancer (sensitivity of only 50-56.5%) 3
- Relying solely on endometrial thickness measurement without tissue sampling is insufficient, as studies show that 7% of patients with initial benign findings may have hyperplasia with atypia or malignancy on follow-up sampling 4
- Asymptomatic thickened endometrium ≥11 mm warrants endometrial biopsy even without bleeding 1, 5
The EMB procedure is essential as it provides definitive histologic diagnosis, which is critical for detecting endometrial cancer early and improving mortality outcomes.