Endometrial Sampling

The endometrium is sampled when pathology is suspected; this may be when the patient experiences a change in her normal pattern of menstrual bleeding, or when bleeding is unexpected e.g. after the menopause.
When a patient presents with any of these symptoms the GP should undertake a full pelvic examination, including speculum examination of the cervix
Guidelines are available on when to refer urgently.¹

• Nulliparity
• Family history of endometrial or colonic cancer
• Tamoxifen or unopposed oestrogens
• Polycystic ovary syndrome
• Obesity

• Transvaginal ultrasound measurement of endometrial thickness has become a routine procedure and an initial investigation in patients with abnormal uterine bleeding.
• There is debate as to whether a cut-off of 5 or 4 mm endometrial thickness should be employed.
• If the endometrial thickness is above these values, polyps have been diagnosed or the patient is presenting with recurrent bleeding, endometrial disease has to be excluded by histological assessment.
• Outpatient aspiration curettage has superseded dilatation and curettage³, which was previously considered to be the gold standard for obtaining endometrial tissue, and provides the same sensitivity in detecting endometrial disease.
• Hysteroscopy allows visualisation of the uterine cavity and the opportunity for targeted biopsy and removal of endometrial polyps.

• Performed without prior cervical dilatation.
• Introduced in the 1930s using narrow metal cannula with side opening with serrated edges and syringe attached for suction as instrument removed.
• As the cannula is rotated during removal, a strip of endometrium is peeled off and sucked into the syringe.
• Causes significant cramping during removal.
• More recent alternative is the Vavra curette requiring vacuum source and also causing significant cramping.
• Recent research has trialled transcervical instillation of 5mls 2% lignocaine. This significantly reduced pain during endometrial sampling.⁵

Today, the most popular device is the disposable Cornier's pipelle⁶.

See related article on the procedure involved in pipelle endometrial sampling.

• Bimanual examination to asses the uterus.
• The cervix is then visualised and cleaned.
• A tenaculum is applied to the anterior lip of the cervix, and is used to provide gentle traction whilst a sound is inserted though the cervical os. This minimises the risk of perforation.
• Dilators may be required if there is difficulty in passing the sound.
• When the position and size of the uterine cavity have been assessed, the pipelle is inserted through the cervical os and advanced until gentle resistance is felt.
• The inner piston of the device is then withdrawn to create a suction and the endometrial sample is obtained by moving the pipelle up and down within the uterine cavity by approximately 2-3cm but not beyond the cervical os.
• This procedure should be repeated at least four times and the device rotated 360 degrees to ensure adequate coverage of the area.
• The pipelle is then withdrawn from the cervical os and the endometrial sample expelled into a solution of formalin for transport to the laboratory.

Pipelle endometrial sampling can also be combined with hysteroscopy.
Other devices include Gravlee 'jet washer', Mi-Mark spiral sampler, Gynoscann surface stripper (based on IUCD insertion principle).

These include;

• Prolonged bleeding
• Infection
• Uterine perforation and post procedure pain
• Bacteraemia can occur after endometrial sampling and antibiotic prophylaxis must be given to patients at risk of endocarditis.⁷

Has been traditional technique for obtaining samples of endometrium for pathological examination.
However, ' blind ' D and C has been shown to miss significant amounts of pathology including;

• Endometrial polyps
• Intrauterine mucous fibroids
• Small areas of endometritis
• Hyperplasia or cancer
• Lost IUDs

• Uterine perforation. This is rarely serious with healing usually rapid and complete.
• It is more common in post-menopausal or post-partum women.
• False passage in cervix or cervical damage producing cervical incompetence from large dilator.
• Infrequently postoperative infection or intrauterine adhesions.

Hysteroscopy is gold standard but not always readily available.

• 3-5mm deep biopsy obtained with hysteroresectoscope loop.
• This is used to identify adenomyosis or investigate deep lesions of the endometrium.
• Permanently removes a narrow strip of basal endometrium with underlying myometrium.
• Usually heals well.