Bleeding (Postmenopausal)

• Speculum examination is invasive and can be distressing for patients and informed consent should be obtained beforehand
• It is performed as it may reveal a source of bleeding, including cervical, vaginal or perineal
• Ensure the patient is up-to-date with their cervical screening tests as appropriate

• If not contraindicated and with informed consent, transvaginal ultrasonography is the method of choice to evaluate the endometrium 4
• Transvaginal ultrasonography may be inappropriate in patients who experience vaginismus, have secondary vaginal stenosis, or do not provide informed consent
• Endometrial thickness should be measured in the sagittal plane and include both endometrial layers. It should be measured at the point where it appears thickest and be perpendicular to the midline. The measurement should be reported in millimetres and rounded up to the closest one decimal point. 3
• If intracavitary fluid is present, the individual thickness of each endometrial layer should be measured and their measurements added together (rather than including the intracavitary fluid in the measurement)
• Evaluation of endometrial morphology includes consideration of endometrial echogenicity (hyperechogenic, isoechogenic, hypoechogenic as compared to the echogenicity of the myometrium) and the endometrial-myometrial junction (regular, irregular, interrupted or not defined) 4

• Bleeding after the first 6 months of continuous combined Menopausal Hormone Therapy (MHT) regimen should be investigated and unscheduled bleeding whilst on a cyclical regimen should be investigated further 5
• For patients on a cyclical HRT, the optimal timing of an ultrasound examination to detect endometrial lesions is in the estrogen-only phase of the cycle, after the end of withdrawal bleeding, or 5-10 days after the last progesterone tablet, depending on the type of HRT 4, 6
• The British Menopause Society guidelines suggest that, for patients on continuous combined HRT, a thickened endometrium requiring sampling is ≧4 mm, whereas those on cyclical HRT should be investigated further if the endometrium is ≧7 mm 7
• However, noting that there is insufficient evidence investigating the effect of different HRT regimens on endometrial thickness, the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) recommends clinicians should be encouraged to consider a conservative approach and use the same endometrial thickness cut-off as patients not on HRT (ie: 4 mm) 6

• Tamoxifen is an estrogen antagonist and part of the drug class of selective estrogen receptor modulators. It is used for patients with estrogen positive breast cancer or for treatment of metastatic breast cancer.
• Tamoxifen has been found to increase the relative risk of endometrial cancer by 2-3 times the risk of the general population 8
• Patients with postmenopausal bleeding on tamoxifen require urgent ultrasound to investigate the presence of cystic stroma, focal changes, increased blood flow and endometrial thickness 6
• Where the endometrium appears thin and regular, this can be followed up with the appropriate specialist, with consideration of endometrial sampling depending on the clinical picture
• The literature has no clear threshold of endometrial thickness to define a thin endometrium in patients on tamoxifen. Rather, the appearance of regularity, lack of focal changes and no increase in vascularization is considered more important.
• In contrast, a thick or irregular endometrium with focal changes and/or abnormal vascularity requires further investigation with saline contrast sonohysterography (if available) and hysteroscopy and endometrial sampling 6

• An endometrial thickness >4 mm may require further evaluation of endometrial morphology and vascularisation using grayscale and Doppler ultrasound imaging with or without the added use of sonohysterography 9-12
• Saha et al 13 suggest that an endometrial threshold of 4 mm has a specificity in TVUS in screening for endometrial cancer of 36%, but a sensitivity of 100%
• Thus, patients with an elevated endometrial thickness >4 mm should be offered hysteroscopic assessment with sampling

Despite a normal endometrial thickness, the following concerning ultrasound features may warrant further investigations, including endometrial sampling: 3, 13-15

• Increased vascularity on colour Doppler
• Altered endometrial homogeneity
• Lack of a uniform three-layer pattern
• The endometrial midline is not regular or linear
• Particulate fluid

• Sonohysterography is used when the endometrium cannot be visualised in its entirety or if there are suspicions of an intracavitary lesion. It involves the injection of sterile fluid into the uterine cavity to enhance visualisation on ultrasound. 4
• Either saline or gel can be used as the negative contrast agent to create an anechoic separation of endometrial layers
• Sonohysterography is contraindicated where there is hydrosalpinx, frozen pelvis, acute pelvic infection or cervicitis 16
• Endometrial sampling can be performed by various methods, including hysteroscopy directed endometrial sampling, uterine curettage or office endometrial sampling