Obstetrics and Gynaecology chapters
Benign gynaecological disorders: fibroids, endometriosis, adenomyosis and ovarian cysts
The common benign conditions of the uterus and ovary: fibroids and their degenerations, adenomyosis, endometriosis, polyps, cervical ectropion and the main benign ovarian cysts, with the tests and treatments PGET asks about.
- Fibroids are benign, oestrogen-dependent smooth muscle tumours; most cause no symptoms, but they can give heavy periods, pressure symptoms and subfertility, and red degeneration causes pain in pregnancy.
- Endometriosis is endometrial tissue outside the uterus (ovary commonest, as a chocolate cyst); adenomyosis is endometrium deep in the myometrium, giving a bulky, tender uterus.
- Benign ovarian cysts range from functional cysts to the dermoid cyst (commonest benign germ cell tumour); torsion is the classic emergency.
On this page
Overview
Benign gynaecological disease fills most gynaecology clinics. The key conditions are:
- Myometrium: fibroids (leiomyomas) and adenomyosis.
- Endometrium and cervix: endometrial polyps, Asherman syndrome, cervical ectropion, Nabothian follicles and cervical polyps.
- Pelvis and ovary: endometriosis and benign ovarian cysts (functional, inflammatory, germ cell, epithelial and sex cord stromal).
Exam questions are usually short scenarios: a woman with a heavy period and a mass, a pregnant woman with a painful fibroid, a young woman with dysmenorrhoea and deep dyspareunia, or a twisted ovarian cyst.
Fibroids (leiomyomas)
What they are
- A benign tumour of uterine smooth muscle. Cut surface: firm, well defined, whorled.
- The commonest tumour in women; found in about 40% of women.
- Commoner in women who are nulliparous, obese, have a family history or are of African descent.
- Usually multiple.
- Oestrogen-dependent: they grow in pregnancy and in later reproductive life, and shrink after the menopause.
Types by position
| Type | Position | Typical effect |
|---|---|---|
| Submucous | Bulges into the uterine cavity | Heavy menstrual bleeding even when small; subfertility and miscarriage; may become a polyp |
| Intramural | Within the muscle wall | Enlarged uterus, heavy periods |
| Subserous | Under the serosa; may be pedunculated | Pressure symptoms; a pedunculated one can twist |
| Cervical | In the cervix | Can block labour or distort the canal |
A small submucous fibroid can cause heavier bleeding than a large subserous one, because it enlarges the bleeding endometrial surface inside the cavity.
Degeneration
Fibroids that outgrow their blood supply can degenerate:
| Type | Features |
|---|---|
| Red (carneous) | Bleeding and necrosis inside the fibroid; acute pain in pregnancy, usually the second trimester |
| Hyaline | Softening into glassy, structureless tissue; no symptoms |
| Cystic | Central necrosis leaves cystic spaces; no symptoms |
| Calcification | Follows old degeneration; may be seen on X-ray as a dense "popcorn" mass in older women |
| Sarcomatous | Very rare, about 1 in 350 or fewer; suspect if a fibroid grows fast after the menopause or there is postmenopausal bleeding |
Leiomyosarcoma arises on its own (de novo), not usually from an existing fibroid. Malignant change in a fibroid is very rare.
Clinical features
- Most fibroids cause no symptoms and need no treatment.
- Abnormal uterine bleeding: heavy menstrual bleeding, sometimes intermenstrual bleeding; may cause iron-deficiency anaemia.
- Pressure ("bulk") symptoms: urinary frequency, bowel symptoms, abdominal swelling; large fibroids can press on the ureters and cause hydronephrosis.
- Subfertility and pregnancy loss: mainly submucous fibroids that distort the cavity.
- Pain is unusual, except with red degeneration or torsion of a pedunculated fibroid.
- Examination: firm, irregular, non-tender enlarged uterus that moves with the cervix (tenderness suggests red degeneration).
Fibroids in pregnancy
- They may enlarge.
- Red degeneration is among the most frequent problems: acute pain, local tenderness, vomiting, sometimes fever. It may trigger miscarriage or preterm labour.
- Management: admit, strong analgesia (often opiates) and IV fluids; it usually settles within a few days.
- Differential: appendicitis, urinary infection, ovarian cyst accident, placental abruption.
- A cervical or lower-segment fibroid can cause an abnormal lie or obstruct labour.
- After delivery: postpartum haemorrhage from poor uterine contraction.
Investigations
| Test | Role |
|---|---|
| Full blood count | Anaemia from heavy bleeding |
| Pelvic ultrasound (transabdominal + transvaginal) | First-line; tells a uterine mass from an ovarian one; checks for hydronephrosis |
| Saline infusion sonography or hysteroscopy | Best for submucous fibroids and polyps |
| MRI | Maps size and position; needed before uterine artery embolisation |
Treatment
No symptoms: observe.
Medical:
- Tranexamic acid, NSAIDs (mefenamic acid), the combined pill and the levonorgestrel IUS control bleeding, but work less well if a fibroid is over 3 cm, submucous, or the uterus is larger than 12 weeks.
- GnRH agonists are the only medical option that shrinks fibroids (by creating a temporary menopause). Side effects: menopausal symptoms and bone loss, so long-term use needs add-back HRT. Fibroids regrow when treatment stops.
- GnRH agonist for 3 months before surgery reduces size and blood loss, and may allow a transverse incision or vaginal route.
- Ulipristal acetate (a selective progesterone receptor modulator) shrinks fibroids but is restricted to refractory cases because of liver injury.
Surgical:
- Hysteroscopic resection: for submucous fibroids; day case.
- Myomectomy (open or laparoscopic): when fertility is wanted. Risks: heavy bleeding (about 1% need an unplanned hysterectomy), adhesions.
- Hysterectomy: definitive, when the family is complete.
Radiological:
- Uterine artery embolisation (UAE): reduces fibroid volume by about half. Risks: pain, fever, infection, fibroid expulsion, ovarian failure. About one-third need further treatment within 5 years; effect on later pregnancy is uncertain.
"Sub-MUCOUS = MUCH bleeding": the submucous fibroid bleeds most for its size.
Adenomyosis
- Endometrial glands and stroma deep within the myometrium.
- Typically a multiparous woman in her late 30s or 40s.
- Symptoms: progressive secondary dysmenorrhoea, heavy menstrual bleeding.
- Sign: uniformly bulky, soft ("boggy"), tender uterus, most tender around menstruation.
- Often coexists with endometriosis.
- Imaging: ultrasound may help; MRI is the best imaging test. Definite diagnosis is only by histology of the hysterectomy specimen.
- Treatment: anything that stops periods helps (LNG-IUS, depot medroxyprogesterone, short-term GnRH agonists). Symptoms come back when treatment stops; hysterectomy is the only definitive cure.
| Feature | Fibroids | Adenomyosis |
|---|---|---|
| Uterus | Irregular, firm, non-tender | Symmetrically bulky, boggy, tender |
| Main symptom | Heavy bleeding, pressure | Painful heavy periods |
| Age and parity | Nulliparous more often | Multiparous, late 30s-40s |
| Plane with myometrium | Well defined | Ill defined |
Endometriosis
Definition and types
Endometrial-type tissue outside the uterine cavity. It is oestrogen-dependent, so it settles after the menopause or with treatment that suppresses the ovary. Three types: superficial peritoneal, deep (infiltrating, e.g. rectovaginal septum, bladder) and endometrioma (ovarian "chocolate cyst" of old blood).
- Affects about 10% of women of reproductive age.
- Commonest site: the ovary; then the pelvic peritoneum, pouch of Douglas and uterosacral ligaments.
- Outside the pelvis: scars (caesarean, laparoscopy), umbilicus, and the chest (catamenial pneumothorax or haemoptysis).
Theories of origin
| Theory | Idea | Explains |
|---|---|---|
| Sampson's implantation (retrograde menstruation) | Viable endometrium flows back through the tubes and implants on the peritoneum | Pelvic disease; most widely accepted |
| Coelomic metaplasia (Meyer) | Peritoneal cells, which share the Müllerian (coelomic) origin, change into endometrium | Disease without menstruation |
| Vascular and lymphatic spread | Endometrial cells carried in vessels | Lung and distant sites |
| Direct implantation | Seeding at surgery | Scar endometriosis |
| Genetic and immune factors | More common in first-degree relatives | Susceptibility |
Clinical features
- Cyclical pelvic pain / secondary dysmenorrhoea, starting before and lasting through the period.
- Deep dyspareunia and dyschezia (painful defaecation): suggest disease in the pouch of Douglas / rectovaginal septum.
- Chronic non-cyclical pelvic pain, fatigue.
- Subfertility in about 30-40%.
- Cyclical haematuria (bladder), cyclical rectal bleeding (bowel).
- Signs: fixed retroverted uterus, tender nodules on the uterosacral ligaments, adnexal mass; the examination may be normal.
The severity of pain does not match the amount of disease. Small deposits can be very painful; extensive disease may be silent.
Investigations
- Transvaginal ultrasound: good for endometriomas ("ground glass" cyst); may show ovaries stuck together ("kissing ovaries").
- MRI: when deep disease is suspected, before surgery.
- CA125 may be mildly raised but is not a diagnostic test.
- Laparoscopy is the gold standard: red, black "powder-burn" or white fibrous lesions; allows biopsy (glands plus stroma confirm it) and treatment in the same sitting.
- Diagnosis is often delayed by years (on average about 7 years).
Management
Medical (for pain; does not improve fertility):
- NSAIDs for symptom relief.
- Combined pill, often back-to-back to stop periods.
- Progestogens: oral, depot medroxyprogesterone, LNG-IUS.
- GnRH agonists: very effective; a brief flare in the first days, then low oestrogen. Not beyond 6 months without add-back HRT because of bone loss.
- Danazol (androgenic ethisterone derivative): weight gain, acne, oily skin, hair growth and deepening of the voice that may not reverse; now rarely used.
- Medical treatment may be started without laparoscopy if examination and scan are normal; operate if no relief after 3-6 months.
Surgical:
- Laparoscopic ablation or excision of deposits; this improves fertility in minimal and mild disease.
- Endometrioma: excise the cyst wall rather than just drain it (lower recurrence) but this costs some ovarian tissue.
- Deep disease needs a specialist centre (bowel and urinary tract risk).
- Pain returns after conservative surgery in up to 30%.
- Hysterectomy with bilateral oophorectomy for women who have finished their family and failed other treatment; HRT afterwards.
Hormonal suppression does not raise the chance of pregnancy in endometriosis, so it is not given to women trying to conceive; surgery for mild disease and IVF are the fertility options.
Endometrial and cervical benign lesions
| Lesion | Key facts |
|---|---|
| Endometrial polyp | Focal overgrowth of glands, stroma and vessels; causes HMB, IMB or postmenopausal bleeding; risk factors: obesity, late menopause, tamoxifen, HRT; diagnosed by hysteroscopy or saline sonography; treated by hysteroscopic polypectomy; about 1% are malignant |
| Asherman syndrome | Intrauterine adhesions after over-vigorous curettage of a recently pregnant or infected uterus; secondary amenorrhoea and subfertility; diagnosed and treated by hysteroscopy |
| Cervical ectropion | Columnar epithelium visible on the ectocervix as a red area; a normal finding due to the "three Ps": puberty, pill, pregnancy; may cause discharge or postcoital bleeding; not an ulcer, so "erosion" is the wrong name |
| Nabothian follicles | Mucus cysts from sealed-over glands in the transformation zone; no significance |
| Cervical polyp | From endocervical epithelium; discharge, IMB, PCB; removed by avulsion |
| Cervical stenosis | After cone biopsy, LLETZ or ablation; trapped blood (haematometra) causes cyclical pain without bleeding |
Benign ovarian cysts
Types
| Group | Examples | Key points |
|---|---|---|
| Functional | Follicular, corpus luteal, theca lutein cysts | Called a cyst when over 3 cm; simple, unilocular; most resolve; less common on the combined pill. Corpus luteal cysts bleed or rupture late in the cycle. Theca lutein cysts go with high hCG (multiple pregnancy, molar pregnancy), often bilateral |
| Inflammatory | Tubo-ovarian abscess | From PID; swinging fever; antibiotics, then drainage if no response |
| Endometrioma | Chocolate cyst | "Ground glass" on ultrasound |
| Germ cell | Mature cystic teratoma (dermoid) | Commonest benign ovarian tumour in young women; contains hair, teeth, fat, skin, cartilage from all three germ layers; bilateral in about 10%; torsion in up to 15%; malignant change rare (under 2%, usually squamous carcinoma in older women); struma ovarii = mostly thyroid tissue |
| Epithelial | Serous cystadenoma, mucinous cystadenoma, Brenner tumour | Serous: usually unilocular, unilateral. Mucinous: very large, multilocular, bilateral in about 10%. Brenner: small, urothelial-type cells |
| Sex cord stromal | Fibroma, thecoma | Fibroma: solid, older women, may twist; Meigs syndrome = fibroma + ascites + pleural effusion, which clears after removal. Thecoma makes oestrogen and causes postmenopausal bleeding and endometrial hyperplasia |
Meigs = "Mass, Effusion, Into the belly (ascites)"; all three settle when the fibroma is removed.
Tumour markers
| Marker | Tumour |
|---|---|
| CA125 | Epithelial ovarian cancer (serous) |
| CA19-9 | Mucinous epithelial tumours |
| AFP | Yolk sac tumour, immature teratoma |
| hCG | Choriocarcinoma, some dysgerminomas |
| Inhibin | Granulosa cell tumour (follow-up) |
Assessment and management
- Transvaginal ultrasound is first-line; pregnancy test in every woman of reproductive age; CRP and white count if abscess or appendicitis is possible; tumour markers if malignancy is a concern.
- Small simple functional cysts: repeat scan, discharge if resolved.
- Dermoid: laparoscopic cystectomy if symptomatic, over 5 cm or growing (it will not resolve on its own).
- In pregnancy, large cysts (over 8 cm) risk torsion, haemorrhage and rupture; torsion is the commonest problem. Planned surgery, if needed, is usually delayed to the late second or early third trimester.
Ovarian torsion
- The ovary twists on its vascular pedicle, cutting off its blood supply. A normal ovary rarely twists; an enlarged one (e.g. dermoid) does.
- Sudden one-sided lower abdominal pain with nausea and vomiting.
- Ultrasound with Doppler helps, but the decision is clinical: emergency laparoscopy to untwist the ovary and remove the cyst (cystectomy). If it is already gangrenous, remove the ovary.
In a young woman with a twisted dermoid, the right operation is to untwist and do a cystectomy to save the ovary, not an oophorectomy, unless the ovary is dead.
Expect: fibroids as the commonest uterine tumour, oestrogen-dependent, shrinking after menopause; submucous fibroid and heavy bleeding; red degeneration in mid-pregnancy managed conservatively; GnRH agonist as the drug that shrinks fibroids and its bone loss; myomectomy for fertility and UAE risks; adenomyosis with a boggy tender uterus and MRI; endometriosis definition, retrograde menstruation, the ovary as the commonest site, deep dyspareunia and uterosacral nodules, laparoscopy as the gold standard; danazol side effects; dermoid contents, bilateral rate and torsion; Meigs syndrome; theca lutein cysts with high hCG; ovarian cyst torsion in pregnancy; ectropion and the "three Ps"; Asherman syndrome after curettage.
Quick revision
- Fibroid: benign smooth muscle tumour, about 40% of women, oestrogen-dependent, usually multiple.
- Submucous fibroid: heaviest bleeding for its size; remove hysteroscopically.
- Red degeneration: pain and tenderness in the second trimester; analgesia, settles in days.
- GnRH agonist shrinks fibroids; add-back HRT protects bone. UAE halves volume.
- Adenomyosis: multiparous, painful heavy periods, boggy tender uterus; hysterectomy is the cure.
- Endometriosis: ovary commonest site; laparoscopy is the gold standard; medical treatment does not help fertility.
- Dermoid: three germ layers, 10% bilateral, torsion; cystectomy.
- Meigs: fibroma + ascites + pleural effusion. Thecoma: oestrogen, postmenopausal bleeding.
- Ectropion: puberty, pill, pregnancy; normal.
Written by The House Job from standard references (Gynaecology by Ten Teachers; Obstetrics by Ten Teachers; Basic and Clinical Pharmacology by Katzung).
FAQ
Do fibroids turn into cancer?
Very rarely. Leiomyosarcoma usually arises on its own; suspect it if a fibroid grows quickly after the menopause or there is postmenopausal bleeding.
Why is a pregnant woman with a fibroid suddenly in pain at 20 weeks?
The fibroid has outgrown its blood supply and undergone red degeneration; she needs admission, analgesia and fluids, and the pain usually settles within days.
Can endometriosis be treated without a laparoscopy?
Yes. If examination and ultrasound are normal, hormonal treatment can be started on clinical grounds; laparoscopy is offered if pain does not improve after a few months.
What is the difference between endometriosis and adenomyosis?
Both involve endometrium in the wrong place: in endometriosis it lies outside the uterus, while in adenomyosis it lies within the muscle of the uterine wall.
Why does a fibroma cause fluid in the chest?
This is Meigs syndrome; the tumour is linked with ascites that can pass into the chest, and both collections clear once the fibroma is removed.