Postmenopausal bleeding and urgent cancer exclusion

Postmenopausal bleeding is bleeding from the genital tract after 12 months of spontaneous amenorrhoea due to menopause. Clarify whether menopause was spontaneous, surgical or treatment-induced and whether HRT creates scheduled withdrawal bleeding. Ask amount, recurrence, pain, discharge, weight change and source, because haematuria and rectal bleeding are sometimes reported as vaginal. Include anticoagulants, tamoxifen, diabetes, obesity, PCOS history, family cancer history and previous endometrial hyperplasia. Anticoagulation can amplify bleeding but cannot be accepted as the diagnosis.

Cancer exclusion is the organizing priority. NICE NG12 recommends a suspected-cancer pathway referral for unexplained PMB in patients aged 55 and older and advises considering it under 55. Referral should not wait for repeated episodes, anaemia or a primary-care ultrasound. Most PMB is benign, often genitourinary atrophy or a polyp, but prevalence does not identify the individual patient. Explain the need for urgent assessment without saying cancer is inevitable.

Examination localises other sources. Inspect vulva for lesions and dermatoses and use a consented speculum examination to assess atrophic mucosa, trauma, discharge, cervical polyp and suspicious cervix. A bimanual examination may identify uterine or adnexal mass. Cervical screening is not a diagnostic test for symptomatic bleeding. If urine or rectal bleeding is plausible, investigate that system while maintaining the uterine pathway until the source is secure.

Transvaginal ultrasound measures the maximum anterior-posterior double-layer endometrium in the sagittal plane and assesses uniformity, focal lesions, fluid, uterus and adnexa. A clear uniform lining of 4 mm or less is used by many UK PMB pathways to identify a low probability of endometrial cancer after a first episode. Thickness above 4 mm, inability to visualise the whole endometrium, irregularity or a focal lesion prompts tissue and cavity assessment. A single thin measurement does not overrule recurrent bleeding.

Histology establishes hyperplasia and cancer. An outpatient Pipelle biopsy samples the endometrium without direct visualisation and is useful for diffuse disease, but focal polyps and localised lesions may be missed. Hysteroscopy directly inspects the cavity and allows targeted biopsy or polypectomy. Insufficient tissue is not automatically negative; interpret it with endometrial thickness, image quality, recurrence and risk. Persistent or recurrent PMB after benign assessment generally requires hysteroscopy or specialist re-evaluation.

HRT bleeding needs regimen-specific timing. Continuous combined HRT aims for amenorrhoea after adjustment, while sequential HRT produces expected cyclical withdrawal bleeding. The BMS joint guideline allows low-risk regimen adjustment for some bleeding within six months of starting or within three months of changing HRT. It advises urgent transvaginal ultrasound within six weeks when first bleeding occurs later than those intervals, or at any time when bleeding is heavy, prolonged or accompanied by relevant cancer risk.

Endometrial thresholds differ on HRT because progestogen schedule changes the lining. When the entire endometrium is uniform, BMS regards 4 mm or less on continuous combined HRT and 7 mm or less on sequential HRT as reassuring enough for regimen adjustment and safety-netting in low-risk patients. Greater thickness, focal abnormality, incomplete visualisation or persistent bleeding triggers urgent endometrial assessment. Do not apply the 7 mm sequential threshold to continuous combined HRT or to a non-HRT symptomatic patient.

Tamoxifen stimulates heterogeneous cystic endometrial change and polyps, reducing the value of a simple thickness threshold. PMB on tamoxifen generally needs specialist direct cavity and histological assessment. Other causes include vaginal or endometrial atrophy, polyps, hyperplasia, endometrial cancer, cervical cancer, vulval disease, infection and trauma. Ovarian oestrogen-producing tumours are uncommon but considered with a mass or unexpected endometrial proliferation.

Management follows diagnosis. Offer vaginal moisturisers, lubricants or local oestrogen for symptomatic genitourinary atrophy after appropriate assessment, with breast-cancer and hormone context considered. Remove symptomatic polyps and manage hyperplasia according to histology and fertility or surgical context. Endometrial cancer is referred to the gynaecological oncology team for staging and treatment. Every benign discharge plan must specify that recurrent spotting, blood-stained discharge or bleeding should return promptly.