Page 14 of 24

OG32.2 | Post-Menopausal Bleeding — SDL Guide (Part 2)

Investigation of PMB — The TVS Rule and Endometrial Sampling

The investigation of PMB is guided by the cardinal principle that endometrial carcinoma must be excluded in every woman with PMB before any other cause is attributed. The investigation pathway is structured and sequential.

Step 1 — Clinical assessment: Full history (duration, amount, associated symptoms — pain, discharge, post-coital component), medication history (HRT, tamoxifen), risk factor assessment. Examination: abdominal palpation (uterine size, masses), speculum examination (cervix, vaginal walls, vulva — to identify obvious cervical or vaginal pathology), and bimanual pelvic examination (uterine size, mobility, adnexal masses).

Step 2 — Transvaginal ultrasound (TVS): The first-line investigation. The key measurement is endometrial thickness: in a postmenopausal woman not on HRT, an endometrial thickness of >4 mm (or >5 mm per some guidelines) requires endometrial sampling to exclude carcinoma. The probability of endometrial carcinoma with a thickness ≤4 mm is approximately 1% — low but not zero, so if bleeding recurs in a woman with a thin endometrium on initial TVS, re-investigation is mandatory. TVS also evaluates the ovaries (adnexal masses suggesting granulosa cell tumour or metastatic disease) and detects endometrial polyps (focal lesion with a vascular pedicle on Doppler).

Step 3 — Endometrial sampling: (a) Pipelle endometrial sampler — an office-based flexible suction curette that obtains an endometrial aspirate without anaesthesia; it has a sensitivity of approximately 90% for endometrial carcinoma and is the most practical first-line biopsy method. It samples only ~4% of the endometrial surface and may miss focal lesions (polyps, early cancer). (b) Hysteroscopy with directed biopsy — the gold standard for evaluating the endometrial cavity; it directly visualises the endometrium, identifies polyps and focal lesions, and allows targeted biopsy of suspicious areas. Indicated when Pipelle result is insufficient, when TVS suggests a focal lesion, or when bleeding persists despite normal Pipelle biopsy.

Additional investigations: MRI pelvis is essential for staging once endometrial carcinoma is confirmed — it assesses myometrial invasion depth, cervical involvement, and lymph node enlargement. CT chest-abdomen-pelvis for metastatic staging. CA-125 — may be elevated in advanced endometrial carcinoma but is non-specific. Cervical biopsy if speculum reveals cervical abnormality.

Algorithm for Investigation of Post-Menopausal Bleeding: TVS Rule and Endometrial Sampling Pathway

Staging of Endometrial Carcinoma

Endometrial carcinoma is staged surgically (not clinically) using the FIGO 2009 staging system (the most widely used in practice; a 2023 update has been published but is not yet universally adopted in Indian examinations). Staging is determined by the findings at total abdominal hysterectomy (TAH), bilateral salpingo-oophorectomy (BSO), and lymph node sampling.

FIGO Stage I — tumour confined to the uterine corpus: Stage IA — myometrial invasion less than 50% of the myometrial thickness; Stage IB — myometrial invasion 50% or more. Stage II — tumour invades the cervical stroma (cervix not merely endocervical glandular involvement). Stage III — local and/or regional spread: IIIA — tumour invades the serosa of the uterus or adnexa; IIIB — vaginal and/or parametrial involvement; IIIC1 — metastasis to pelvic lymph nodes; IIIC2 — metastasis to para-aortic lymph nodes. Stage IV — distant spread: IVA — tumour invades bladder or bowel mucosa; IVB — distant metastases including inguinal lymph nodes or intraperitoneal disease.

Grade also stratifies prognosis: Grade 1 (well differentiated, ≤5% non-squamous solid growth), Grade 2 (6–50% solid), Grade 3 (>50% solid or clearly non-squamous). Stage IA Grade 1–2 tumours carry an excellent prognosis with surgery alone (5-year survival >90%). Stage IB or higher, or Grade 3, or Type II histology are considered high-risk and require adjuvant treatment. Approximately 70–75% of endometrial carcinomas are diagnosed at Stage I — primarily because PMB prompts early investigation.

FIGO 2023 Staging of Endometrial Carcinoma — Diagrammatic Summary

Management of PMB by Cause

Management of PMB depends entirely on the established cause following investigation. The cornerstone of management is that no patient with PMB should be reassured and discharged without either a confirmed benign histological diagnosis or a documented rationale for not sampling.

Endometrial carcinoma: The primary treatment is surgical — total abdominal hysterectomy (TAH) + bilateral salpingo-oophorectomy (BSO) + pelvic and para-aortic lymph node assessment. Laparoscopic and robotic approaches are now standard in most centres. Lymph node dissection or sentinel node biopsy determines IIIC staging. Adjuvant treatment is guided by stage and risk stratification: Stage IA Grade 1–2 — no adjuvant treatment; Stage IB or Grade 3 or Type II histology — vaginal brachytherapy (reduces vaginal vault recurrence) or external beam radiotherapy (EBRT) for high-risk features; Stage III–IV — combination pelvic EBRT + chemotherapy (carboplatin + paclitaxel); for advanced or recurrent disease, hormonal therapy (progestogens, e.g. medroxyprogesterone acetate) or immunotherapy (pembrolizumab for MSI-high tumours). Women who are medically unfit for surgery may receive primary radiotherapy.

Endometrial polyp: Hysteroscopic polypectomy under direct vision, with histological examination of the resected polyp. Malignant change within a polyp can occur, so all polyps should be sent for histology.

Endometrial atrophy: If histology confirms simple atrophy with no hyperplasia or malignancy, topical/local vaginal oestrogen may relieve symptoms. Reassurance that bleeding is benign can be given, but the patient must be advised to re-present if bleeding recurs (a second episode of PMB requires re-investigation even after a previously normal biopsy).

HRT-related bleeding: Adjust the HRT regimen — switch from sequential to continuous combined, reduce the dose, or change the progestogen type. Perform endometrial sampling if unscheduled bleeding persists beyond 6 months on continuous combined HRT.

Cervical pathology: Colposcopy, cervical biopsy, and LLETZ (loop excision of the transformation zone) for cervical intraepithelial neoplasia or early invasive cervical carcinoma; staging and appropriate management for invasive cervical carcinoma.

Provided image

Self-Assessment

Consolidate the following core rules about post-menopausal bleeding. First, PMB is defined as vaginal bleeding ≥12 months after the last period — this is an alarm symptom requiring urgent investigation without exception. Second, the cardinal rule: PMB is due to endometrial carcinoma until proven otherwise — approximately 10% of PMB is endometrial carcinoma, but clinical examination cannot distinguish malignant from benign causes. Third, the TVS endometrial thickness rule: in a postmenopausal woman not on HRT, thickness >4–5 mm mandates endometrial sampling; ≤4 mm is reassuring (~1% malignancy risk) but the patient must return if bleeding recurs. Fourth, the investigation sequence is: clinical examination (speculum mandatory) → TVS → Pipelle biopsy (first-line) or hysteroscopy + directed biopsy (gold standard). Fifth, endometrial carcinoma causes: Type I (80%) = oestrogen-driven endometrioid, risk factors are obesity/nulliparity/DM/unopposed oestrogen; Type II (20%) = serous/clear cell, oestrogen-independent, high-grade, poor prognosis. Sixth, FIGO surgical staging: Stage I (uterine corpus — IA <50% myometrium, IB ≥50%), Stage II (cervical stroma), Stage III (local-regional), Stage IV (bladder/bowel/distant). Seventh, treatment of endometrial carcinoma: TAH+BSO+lymph node assessment, with adjuvant radiotherapy/chemotherapy for Stage IB or higher or Grade 3. A second episode of PMB always requires re-investigation, even after previously normal findings.