Cervical Ectropion

Introduction

Cervical ectropion (also called cervical erosion or ectopy) is the eversion of the endocervical columnar epithelium onto the surface of the ectocervix, so that it extends beyond the normal squamocolumnar junction and becomes visible on speculum examination.¹ It is a normal physiological variant rather than a disease process, and understanding this distinction is the single most important thing to take from this topic.

The cervix is normally covered by two types of epithelium meeting at the squamocolumnar junction: smooth, pale pink squamous epithelium on the ectocervix (the part visible on speculum examination), and red, glandular columnar epithelium lining the endocervical canal. In an ectropion, hormonal changes cause the squamocolumnar junction to move outward, exposing the more delicate columnar epithelium on the ectocervix where it is visible and vulnerable to contact bleeding.

Aetiology

Ectropion is driven by oestrogen, which causes the cervix to enlarge and the squamocolumnar junction to evert outward.¹ It is therefore common and physiological in situations of high oestrogen exposure:

• Adolescence and the reproductive years, particularly soon after menarche
• Pregnancy
• Combined hormonal contraceptive use (the pill, patch or ring)
• Less commonly, exogenous oestrogen exposure from other sources

As oestrogen levels fall - after pregnancy, on stopping combined hormonal contraception, or after the menopause - the columnar epithelium typically undergoes squamous metaplasia, transforming into more resilient squamous epithelium and the ectropion regresses. This transformation zone, where columnar epithelium is gradually replaced by metaplastic squamous epithelium, is clinically important because it is where the great majority of cervical intraepithelial neoplasia and cervical cancers arise (see the cervical cancer article).

Clinical features

Ectropion is very often asymptomatic and found incidentally during a speculum examination or cervical screening test.² When symptomatic, features reflect the fact that columnar epithelium is thinner, more vascular, and produces more mucus than squamous epithelium:

• Increased vaginal discharge, typically clear or mucoid
• Postcoital bleeding (spotting after intercourse, from contact trauma to the fragile columnar epithelium)
• Intermenstrual spotting, particularly light bleeding
• Usually painless and without associated systemic symptoms

On speculum examination, an ectropion appears as a well-defined, red, velvety ring of tissue around the external os, contrasting sharply with the smoother, paler pink squamous epithelium of the rest of the ectocervix. This appearance can look alarming to an inexperienced examiner, but the well-demarcated, symmetrical, uniform appearance is reassuring and typical of a benign ectropion rather than malignancy.

Differential diagnosis and red flags

Because ectropion, cervicitis and early cervical cancer can all cause a red-appearing cervix and postcoital bleeding, they must be carefully distinguished, and ectropion should always be treated as a diagnosis of exclusion in the presence of any red flag feature.³

Investigations

A classic-appearing ectropion in a woman with an up-to-date, normal cervical screening history and no red flag features needs no further investigation beyond the clinical examination itself.² If there is any diagnostic uncertainty, or symptoms warrant it:

• Ensure cervical screening (HPV/cytology) is up to date - perform opportunistically if due
• Endocervical and high vaginal swabs if infection (chlamydia, gonorrhoea, bacterial vaginosis) is suspected as a cause of discharge or bleeding
• Colposcopy and biopsy if the cervix has an atypical or suspicious appearance, or bleeding persists despite treatment of an identified benign cause

Management

No treatment is needed for an asymptomatic ectropion - this is a normal finding, and the priority is reassurance rather than intervention.¹

For women with troublesome symptoms (persistent discharge or recurrent postcoital bleeding) once other causes have been excluded, options include:

• Stopping combined hormonal contraception (switching to a non-oestrogen-containing method), which allows the ectropion to regress as oestrogen exposure falls
• Cervical cautery or ablation (e.g. cryotherapy, electrocautery, or silver nitrate application) to destroy the columnar epithelium and encourage re-epithelialisation with squamous epithelium, reserved for persistent symptomatic cases

Prognosis

Cervical ectropion is entirely benign and typically regresses spontaneously as oestrogen exposure falls - after pregnancy, on stopping combined hormonal contraception, or with the menopause. It does not increase the risk of cervical cancer, does not require treatment in the absence of bothersome symptoms, and has no effect on fertility. Ongoing routine cervical screening according to the national programme remains the relevant preventive measure, entirely independent of whether an ectropion is present.