Clinical overview
Most of what a registrar sees on the cervix in a busy South African gynaecology or family-planning clinic is benign. Ectropion, polyps, Nabothian cysts, cervicitis and benign metaplasia together account for the great majority of "abnormal-looking" cervices, abnormal discharge, and post-coital or intermenstrual bleeding referred for colposcopy. The pathophysiology of these conditions is, at root, the physiology of the cervix itself — the dynamic remodelling of the transformation zone under oestrogen, the response of columnar epithelium to a low vaginal pH, and the reaction of cervical stroma and glands to mechanical and infective insult. Understanding that physiology is what lets you confidently reassure most women, while never missing the cancer hiding behind an identical clinical picture.
The exam-relevant tension is precisely that overlap. Cervical ectropion and an early invasive carcinoma can both present as a friable, contact-bleeding cervix; a benign endocervical polyp and an early endometrial or cervical neoplasm can both present as intermenstrual bleeding. In a country with one of the highest cervical-cancer burdens in the world — driven by very high HIV prevalence and historically patchy screening coverage — the discipline is to treat benign cervical disease as a diagnosis of exclusion that is reached through the screening and colposcopic pathway, not around it. This chapter describes the pathophysiology of the common benign lesions and frames them firmly inside the South African screening reality and the WHO 90-70-90 elimination agenda.
Core knowledge
The transformation zone — the engine of benign cervical change
The ectocervix is lined by non-keratinised stratified squamous epithelium continuous with the vagina; the endocervical canal is lined by a single layer of mucin-secreting columnar epithelium thrown into deep clefts and crypts (often loosely called "glands", though they are infoldings rather than true acini). The junction between them — the squamocolumnar junction (SCJ) — is not fixed. Its position migrates over a woman's life under hormonal control, and the band of epithelium between the original SCJ and the current SCJ is the transformation zone (TZ).
Two processes drive almost all benign (and indeed neoplastic) cervical change in the TZ:
- Eversion (ectropion). Under high oestrogen states — puberty, the reproductive years, pregnancy, and combined oral contraceptive use — the cervix grows and the canal everts, exposing the soft red columnar epithelium onto the ectocervix.
- Squamous metaplasia. Once columnar epithelium is exposed to the acidic vaginal environment (pH ~3.5–4.5, maintained by lactobacilli), the relatively fragile single-cell layer is progressively replaced by more robust squamous epithelium. This is a normal, physiological, protective adaptation — metaplasia, not dysplasia. It begins with reserve-cell hyperplasia beneath the columnar cells, which then differentiate into immature and finally mature squamous epithelium.
The metaplastic TZ is biologically the most important real estate in gynaecological oncology: it is the actively dividing, susceptible epithelium where high-risk HPV establishes persistent infection and where essentially all squamous cervical neoplasia arises (see cervical-carcinogenesis and hpv-pathology). The same physiology that produces benign metaplasia is the substrate for malignant transformation — which is exactly why benign and pre-malignant disease share a clinical appearance.
Cervical ectropion (ectopy)
Figure D6.1 — Cervical ectropion/ectopy: hormone-driven eversion of columnar epithelium onto the ectocervix — normal physiology that mimics cancer.
Ectropion is the visible presence of endocervical columnar epithelium on the ectocervix. It is not a disease, an erosion, or a pre-malignant condition — the older term "cervical erosion" is a misnomer because nothing is eroded; the epithelium is simply everted and exposed. Macroscopically it appears as a well-demarcated red, sometimes granular or "strawberry" zone around the external os, contrasting with the pale pink squamous ectocervix.
The columnar epithelium is a single cell thick over a rich subepithelial capillary network, which explains the two cardinal features:
- Friability and contact bleeding — the thin epithelium is easily traumatised (intercourse, speculum, swab), producing post-coital or contact bleeding.
- Increased mucoid discharge — exposed mucin-secreting columnar cells produce more clear/mucoid discharge than squamous epithelium would.
Drivers are the high-oestrogen states listed above; ectropion is therefore common in adolescents, pregnant women, and combined-pill users, and tends to regress after menopause as oestrogen falls and the SCJ recedes into the canal. Histologically there is normal columnar (or partly metaplastic) epithelium with no atypia. The clinical importance is entirely in its mimicry: a friable, bleeding cervix is also the presentation of cervicitis, of HPV-related disease, and of early invasive carcinoma. Ectropion is a diagnosis of exclusion made after malignancy has been ruled out by appropriate screening/colposcopy.
Cervical polyps
Figure D6.2 — Two benign cervix bumps: Nabothian (mucus-retention) cysts vs fibrovascular endocervical polyps — formation, appearance and management.
Cervical polyps are the commonest benign neoplastic-looking growths of the cervix, most frequent in multiparous women in the fourth-to-sixth decades. They are pedunculated or sessile overgrowths arising either from the endocervical canal (endocervical polyps, the majority) or from the ectocervix.
Pathophysiology is best understood as a focal hyperplastic/inflammatory response: chronic inflammation, local hyperaemia, and hormonal (oestrogenic) stimulation drive focal proliferation of endocervical epithelium and stroma. Macroscopically they are smooth, red-to-purple, soft, often a few millimetres to a couple of centimetres, frequently protruding through the external os on a stalk. Microscopically the typical endocervical polyp has a fibrovascular/oedematous stromal core covered by endocervical columnar epithelium, often with squamous metaplasia at the surface, dilated mucous glands, and a chronic inflammatory infiltrate; surface ulceration accounts for bleeding. Variants include fibrous, vascular, and (rarely) adenomyomatous polyps.
Clinically they cause intermenstrual, post-coital, or post-menopausal bleeding and discharge, though many are asymptomatic and found incidentally at speculum examination. Malignancy within a cervical polyp is rare (well under 1%), but it is not zero — which is why every removed polyp goes for histology, and why a polyp in a post-menopausal woman or one associated with abnormal bleeding mandates assessment of the endometrium as well, since the bleeding may be endometrial in origin and the polyp coincidental.
Nabothian cysts, tunnel clusters and other benign entities
- Nabothian (retention) cysts. When advancing squamous metaplasia overgrows the openings of endocervical crypts, trapped mucin distends the crypt into a mucus-retention cyst. They appear as smooth, yellowish-white, often translucent dome-shaped cysts on the ectocervix, single or multiple, and are an entirely normal consequence of physiological metaplasia. They need no treatment. On imaging, deep or florid ("tunnel cluster") versions can occasionally mimic adenoma malignum, which is the relevant pitfall.
- Microglandular hyperplasia. A benign proliferation of endocervical glands classically associated with progestational states (combined pill, pregnancy, postpartum). It can form a friable polypoid lesion and can mimic adenocarcinoma histologically — a recognised diagnostic trap for the pathologist.
- Cervicitis. Acute or chronic inflammation of the cervix, frequently infective. In the South African context the key pathogens are Chlamydia trachomatis and Neisseria gonorrhoeae (mucopurulent cervicitis), Trichomonas vaginalis, and herpes simplex (see sti-pathology). Cervicitis produces oedema, hyperaemia and friability — again clinically indistinguishable at a glance from ectropion or neoplasia, and managed syndromically under SA STI guidelines.
- Endometriosis and decidualisation. Ectopic endometrial tissue on the cervix, and pregnancy-related decidual change, can both produce friable, bleeding lesions that mimic malignancy.
WHO-2020 terminology and the benign–neoplastic boundary
It is worth fixing the terminology the exam expects. Under the WHO Classification of Tumours of the Female Genital Tract, 5th ed (2020), which adopts the LAST/2014 two-tier system, squamous intraepithelial lesions are graded as LSIL (low-grade SIL, equivalent to CIN 1) and HSIL (high-grade SIL, equivalent to CIN 2–3), and lesions are further framed as HPV-associated versus HPV-independent. The conditions in this chapter — ectropion, polyps, Nabothian cysts, metaplasia, microglandular hyperplasia, cervicitis — sit outside the SIL spectrum: they are benign, with no epithelial atypia. The whole clinical task is to distinguish them confidently from LSIL/HSIL and invasive disease, because they look the same to the naked eye. Squamous metaplasia in particular must never be over-called as dysplasia (see cin-pathophysiology).
Assessment
Figure D6.3 — Benign or biopsy? Typical benign cervical patterns vs the suspicious features that demand biopsy/urgent colposcopy.
The assessment of a benign-looking cervix is the assessment that excludes cancer. Take a focused history: the nature and timing of bleeding (post-coital, intermenstrual, post-menopausal), discharge, dyspareunia, contraception (pill use favours ectropion and microglandular hyperplasia), parity, last menstrual period and pregnancy status, HIV status and CD4/viral load, and crucially the woman's cervical-screening history — when last screened, by what test, and the result.
On speculum examination, characterise the lesion: a symmetrical red zone around the os everting from the canal suggests ectropion; a smooth pedunculated mass through the os suggests a polyp; yellowish translucent domes suggest Nabothian cysts; a contact-bleeding, irregular, friable or ulcerated lesion, a hard or fixed cervix, or one that bleeds spontaneously must be treated as cancer until proven otherwise. Bimanual examination assesses cervical size, mobility and any parametrial induration.
Investigations are anchored to the South African cervical-screening pathway. SASOG/BetterGyn (2024) and NDoH policy are moving the country toward HPV-DNA primary screening (informed by the DiaVACCS trial), with triage by genotyping (16/18), cytology or VIA, then treat-by ablation or LLETZ. The legacy public-sector cytology policy screened women 30–50 years, three smears at 10-yearly intervals from age 30. The HIV-specific rule is essential and frequently examined: HIV-positive women are screened at the time of HIV diagnosis and more frequently thereafter (approximately 3-yearly), regardless of age, reflecting accelerated HPV persistence and progression. Confirm the exact current interval/algorithm against the live BetterGyn 2024/NDoH document before quoting numbers, as they are being revised.
Practically, in a woman with a friable cervix or abnormal bleeding: do an HPV test/cytology per the screening pathway, take endocervical/vaginal swabs (and treat cervicitis syndromically per SA STI guidelines if indicated), and refer for colposcopy (see colposcopy) if screening is positive, if there is unexplained abnormal bleeding, or if the cervix looks suspicious — colposcopy with directed biopsy is what separates benign mimics from SIL and invasion. A visible polyp can be removed in clinic and sent for histology. Post-menopausal bleeding or an endocervical polyp with abnormal bleeding additionally requires endometrial assessment (transvaginal ultrasound ± endometrial sampling) to exclude an endometrial source (see endometrial-carcinoma).
Management
Management of genuinely benign cervical pathology is conservative and reassurance-led, but always after the cancer pathway has done its work.
Cervical ectropion. Asymptomatic ectropion needs no treatment — it is physiological and regresses with menopause or on stopping the combined pill. For troublesome symptoms (persistent discharge or contact bleeding) once HPV/cytology is negative and malignancy excluded, options include stopping the oestrogen-containing contraceptive (switching to a progestogen-only or non-hormonal method, see contraceptive-modalities) and, if symptoms persist, ablation of the everted columnar epithelium by thermal/cold coagulation or cryotherapy. Ablation is a symptom treatment, not a cancer treatment, and is only appropriate when neoplasia has been excluded.
Cervical polyps. Symptomatic polyps and most accessible polyps are removed. A small pedunculated polyp can be avulsed/twisted off at its base in the clinic (grasp with sponge/polyp forceps and rotate), with the base treated by cautery if it bleeds; broad-based or large polyps, or those where the base cannot be visualised, are better removed under hysteroscopic guidance to ensure complete excision and to identify a possible endometrial origin. Every polyp is sent for histology without exception — the rare malignancy must not be discarded. Asymptomatic small polyps may reasonably be left and observed, but most clinicians remove them given the simplicity and the histological reassurance gained.
Nabothian cysts and metaplasia need no intervention — reassurance only. Microglandular hyperplasia requires no treatment once correctly identified, but the value is in the pathologist not over-calling it as adenocarcinoma. Cervicitis is managed by treating the underlying infection: syndromic management of STIs under the SA STI guidelines, partner notification and treatment, and HIV testing/linkage to care where status is unknown.
Throughout, the South African overlay matters. Because cervical cancer is so common here and HIV so prevalent, the system bias should be toward screening, colposcopy and histology rather than toward labelling-and-discharging on appearance alone. Opportunistic contact with a woman for a benign cervical complaint is also a chance to ensure she is enrolled in screening, that HIV-positive women are on appropriate-interval screening, and to reinforce the WHO 90-70-90 elimination message — including the school-based single-dose HPV vaccination programme (girls 9–14, running in SA since 2014, moving to the broadest-cover nonavalent/single-dose approach endorsed by WHO).
Red flags / pitfalls
- Treating "erosion"/ectropion as benign without screening. The single biggest error: an early invasive cancer looks exactly like a friable, contact-bleeding ectropion. Never ablate or reassure a friable cervix until HPV/cytology and, where indicated, colposcopy have excluded neoplasia.
- Forgetting the endometrium behind a polyp. Intermenstrual or post-menopausal bleeding "explained" by a cervical polyp may actually be endometrial. Assess the endometrium, especially post-menopausally.
- Discarding a removed polyp. Malignancy in a polyp is rare but real — send every one for histology.
- Over-calling metaplasia or microglandular hyperplasia as dysplasia/adenocarcinoma. Squamous metaplasia is normal physiology; microglandular hyperplasia mimics adenocarcinoma. Both are classic pathology traps.
- Under-screening HIV-positive women. They progress faster and must be screened at HIV diagnosis and more frequently thereafter regardless of age; defaulting to the general-population interval misses disease.
- Mistaking florid Nabothian/tunnel clusters on imaging for adenoma malignum. A radiology pitfall; correlate clinically.
- Assuming a hard, fixed, or spontaneously bleeding cervix is benign. These are cancer signs — refer urgently, do not biopsy-and-wait casually.
- Ablating ectropion in a woman who simply needs to stop her combined pill — address the driver first.
Evidence anchors
- South African cervical cancer screening — SASOG/BetterGyn Clinical Guideline (2024) and NDoH National Cervical Cancer Screening / Prevention & Control Policy — the SA source of truth: move to HPV-DNA primary screening (informed by the DiaVACCS trial), historic public-sector cytology policy (screen 30–50, three smears 10-yearly from age 30), and the HIV rule (screen at HIV diagnosis and ~3-yearly thereafter regardless of age). Confirm exact current intervals/algorithm against the live document before quoting numbers.
- WHO Cervical Cancer Elimination Strategy (2020) — 90-70-90 by 2030, single-dose HPV schedule (WHO 2022), nonavalent vaccine, SA school-based programme since 2014 — context for prevention and the screen-don't-discharge bias.
- WHO Classification of Tumours of the Female Genital Tract, 5th ed (2020) — LAST/2014 two-tier terminology (LSIL/HSIL with CIN 1–3 equivalence), HPV-associated vs HPV-independent; the benign lesions here sit outside the SIL spectrum.
- South African STI Management Guidelines (SAHCS 2022 STI Guidelines + NDoH STG/EML) — syndromic management of mucopurulent cervicitis and partner treatment.
- Southern African HIV Clinicians Society 2023 Adult ART Guidelines / SA National HIV-ART Consolidated Guidelines (2023) — context for the high-HIV-prevalence effect on HPV persistence and accelerated cervical disease, and for linkage to care.
(Benign cervical pathology has no dedicated international guideline; the ESGO/ESTRO/ESP cervical cancer 2023 update and FIGO 2018 staging govern the malignant differential it must be distinguished from — see cervical-carcinogenesis — rather than the benign lesions themselves.)