Obs & gynae clinic - postmenopausal bleeding

The case

A 58-year-old postmenopausal woman presents to her GP with a few episodes of vaginal bleeding. She has no risk factors for endometrial cancer. Her GP makes a fast track referral to secondary care where a pelvic ultrasound suggests an endometrial polyp. Outpatient hysteroscopy is arranged but is unsuccessful and endometrial biopsy is inadequate. A further hysteroscopy under general anaesthetic raises a suspicion of endometrial cancer, and an endometrial biopsy confirms endometrial cancer. Following a discussion in a multidisciplinary team meeting, she undergoes a total abdominal hysterectomy and bilateral salpingooophorectomy. She is currently being seen in the regional cancer centre, where she will be offered radiotherapy.

The problem

Postmenopausal bleeding (PMB) is defined as bleeding occurring after 12 months without menses. Endometrial cancer is the most serious potential underlying cause of PMB and is present in approximately 10% of patients referred with PMB.

Risk factors for endometrial cancer include

obesity
nulliparity
polycystic ovary syndrome
use of exogenous oestrogens
tamoxifen - which has an anti-oestrogen effect on the breast, but a pro-oestrogen effect on the uterus
a family history of endometrial cancer – for example, families with hereditary non polyposis colon cancer.

Other malignant causes of PMB are cervical, tubal, vulval and vaginal carcinoma, and oestrogen-producing ovarian tumours.

Benign gynaecological causes of PMB include atrophic vaginitis (the leading cause of PMB), endometrial and cervical polyps, and endometrial hyperplasia.

The use of continuous combined HRT is associated with a reduced relative risk of endometrial cancer but may cause unpredictable spotting or bleeding during initial use.^1,2 Women on sequential HRT should expect to have regular withdrawal bleeding, but there is no specific reason to discontinue HRT prior to referral to secondary care.³ Stopping and restarting HRT increases thrombotic risk.

History

It is important to establish that the bleeding is coming from the vagina and not the urinary tract or bowel. Multiple bleeding episodes, especially during micturition or bowel motions may serve as a pointer to a possible origin of the bleeding. Ask when the bleeding started, how much bleeding there was, how long it lasted for and whether it was a single episode or recurrent bleeding.

Risk factors for endometrial cancer can be sought in the history, but the absence of risk factors should not delay a referral to gynaecology.

Take a medication history – current use and type of HRT, use of anticoagulants, tamoxifen.

Examination

A full pelvic examination, including a speculum examination is the minimum requirement by NICE.⁴ This might be difficult in the primary care setting – there might not be any chaperones available or in situations where the GP sees a patient in a care home.

This should be performed whenever possible - even though the patient is likely to be referred under the two week rule. It only takes an additional 10 minutes but it could make the difference between an inappropriate referral to gynaecology and an appropriate referral to urology or colorectal surgery.

A normal bimanual examination will usually exclude pelvic masses such as large fibroids and ovarian cysts.

A speculum examination allows for inspection of the vagina – look for atrophic vaginitis, carcinoma is rare. Inspect the cervix for polyps, evidence of inflammation and cancer (commonest gynaecological cancer in patients from the developing world). The urethral meatus can be inspected for bleeding and a smear test can be performed if one is due.

A rectal examination may be required if the history suggests PR bleeding.

Investigations

A urinalysis may be useful where urethral bleeding is suspected.

Requesting a pelvic ultrasound scan in women with PMB will delay diagnosis and a scan should not be considered a substitute for referring patients. Even when a scan is requested, a referral should be made at the same time on a fast track form. Some units will have a rapid access service and some will see them directly in a PMB clinic or outpatient hysteroscopy clinic.

Referral

Patients with the following symptoms should be referred as fast track:

Any spotting or vaginal bleeding (bright red or brownish) in a woman after 12 months of amenorrhoea
Any vaginal bleeding in a younger woman more than 12 months after a diagnosis of premature ovarian failure
Any unexpected or significant change in withdrawal bleeding in women on sequential HRT
Any bleeding on continuous combined HRT after six months of use or after amenorrhoea has been established
Unexplained bleeding at least six weeks after stopping HRT
Recurring PMB six months or more after previous normal hysteroscopy assessment
Any bleeding in a woman taking tamoxifen

What happens in hospital?

Pelvic ultrasound scan

This is usually transvaginal (TVS). It is best done within the context of a ‘one-stop’ outpatient hysteroscopy service where the woman has a scan prior to being seen by the hysteroscopist.

If the scan shows a normal pelvis, with an endometrial thickness of 3mm or less and the woman’s bleeding has resolved, then she will be discharged back to primary care, provided the vagina and cervix are normal on inspection.

An endometrial thickness of 3mm or less is associated with a very low probability of endometrial cancer (0.6-0.8%).³ This cut-off is nationally recommended but local guidelines may differ and many hysteroscopists use a cut-off of 4mm.

Hysteroscopy and endometrial biopsy

This should be done as an outpatient procedure in most cases. The indications include women with an endometrial thickness of more than 3mm on ultrasound scan, and women with bleeding on tamoxifen as ultrasonography is poor at differentiating potential cancers from other tamoxifen-induced thickening.³

An endometrial biopsy is obtained at the same time. The woman is discharged if hysteroscopy and histology are normal. An endometrial polyp, if found, will usually require removal under a general anaesthetic.

Endometrial cancer is discussed in a gynaecology multi-disciplinary team meeting, where a management plan is made.

Dr Tayo Bajulaiye is a senior obstetrics registrar at Bradford Teaching Hospitals NHS Foundation Trust.

Professor Sian Jones is a consultant in obstetrics and gynaecology at Bradford Teaching Hospitals NHS Foundation Trust.

References