GC118 Pelvic Mass Ovarian Cancer And Cysts; Uterine Fibroid; Pelvic Imaging
Pelvic masses encompass ovarian cysts and cancers as well as uterine fibroids, evaluated through imaging modalities such as ultrasound, CT, and MRI to determine their origin, characteristics, and malignant potential.
Pelvic Mass: Ovarian Cancer & Cysts, Uterine Fibroids, and Pelvic Imaging
This GC 118 lecture by Dr. Ka Yu Tse covers the systematic clinical approach to a pelvic mass — from history and examination through differential diagnosis, investigation (with emphasis on pelvic imaging), to management. The three pillars are:
- Uterine fibroids (leiomyomas) — the most common uterine neoplasm
- Ovarian cysts — benign adnexal masses and their complications
- Ovarian cancer — malignant ovarian tumours with staging, risk stratification tools (IOTA, RMI, ROMA, ADNEX), and management principles
Why this matters for exams: Pelvic mass is a favourite exam topic because it tests history-taking structure, systematic DDx generation, ultrasound interpretation, tumour marker knowledge (CA-125 pitfalls), and management decision-making based on age, menopausal status, and malignancy risk. Past papers have directly tested fibroid management (2018 SAQ Q11), ovarian mass ultrasound features (2022 SAQ Q12), and pelvic imaging modality choice (2025 MCQ Q1). [1][2][3][4]
How the lecture is structured:
- A. History taking → B. Physical examination → C. Differential diagnoses → D. Investigation & Pelvic imaging → E. Treatment
A. History Taking for Pelvic Mass
The lecture emphasises a structured gynaecological history: Age → Chief complaint details → Related symptoms → Menstrual history → Obstetric history → Sexual/contraception history → Family/drug/medical/surgical/allergy history. [1]
| Element | Why It Matters |
|---|---|
| Onset: how was the mass discovered | Incidental finding on imaging vs. patient-noticed lump changes your differential (incidental = more likely benign/asymptomatic fibroid) |
| Size and site | Suprapubic midline → uterine origin; lateral → adnexal; right iliac fossa → must also consider appendiceal/caecal pathology |
| Duration and change since first noted | Interval change matters, but rapid fibroid growth alone is not a reliable discriminator of leiomyosarcoma; new postmenopausal growth, atypical imaging, bleeding and systemic features need specialist assessment [21] |
| Associated symptoms: distension, pressure symptoms | Distension may be the mass itself OR ascites (critical distinction — ascites suggests malignancy) |
Menstrual pattern (regularity, amount), dysmenorrhoea, and associated symptoms (abdominal pain pattern, urinary/bowel symptoms, constitutional symptoms). [1]
- Compare with previous pattern — this is crucial. A woman who has always had heavy periods is different from one whose flow suddenly changed.
- Timing: Duration of flow, cycle length
- Amount of flow: Number of pads/tampons, clots, flooding, double protection
- Anaemic symptoms: Fatigue, dyspnoea on exertion, palpitations, dizziness
- DDx for heavy menstrual flow: fibroid, adenomyosis [1]
| Type | Features | DDx |
|---|---|---|
| Primary | Begins soon after menarche; prostaglandin-mediated cramping without an identified pelvic disorder | Usually functional; investigate when severe, atypical or treatment-resistant |
| Secondary | No previous history of dysmenorrhoea; associated with menorrhagia, subfertility | Adenomyosis is the key DDx; also endometriosis, fibroids |
Why distinguish? The slide's wording can be misread as saying early-onset primary dysmenorrhoea implies structural disease. Current teaching is the opposite: primary dysmenorrhoea is usually functional, while new, progressive, persistent or treatment-resistant pain raises concern for secondary causes such as endometriosis, adenomyosis or fibroids. [15]
Due to pressure effect or invasion. DDx includes gynaecological diseases, non-gynaecological pathologies, and secondary ovarian cancer from bowel primary. [1]
Exam Trap
Don't forget that a pelvic mass causing bowel symptoms could be a primary bowel cancer (e.g., sigmoid/caecal carcinoma) or a secondary ovarian cancer from a bowel primary (Krukenberg tumour). The lecture explicitly flags this.
| Pathology | Symptoms (from lecture slides) |
|---|---|
| Fibroid | Asymptomatic; Menorrhagia; Abdominal distension; Pressure effect; Anaemia; Others — dysmenorrhoea can happen but not typical |
| Ovarian cyst | Asymptomatic; Abdominal distension (due to cyst or free fluid); Pressure symptoms (urinary/bowel); Abdominal pain due to mass effect or complications — sudden or chronic (torsion, haemorrhage, rupture); Dysmenorrhoea (endometriosis) |
| Ovarian cancer | Asymptomatic; Non-specific GI upset; Abdominal distension; Abdominal pain; Pressure symptoms; Complications (haemorrhage, rupture); Systemic symptoms (weight loss, appetite loss, unexplained fever, lower limb swelling, lymphadenopathy); Symptoms related to metastasis |
Key Discriminator
Fibroid = heavy menstrual bleeding and bulk/pressure symptoms are common; acute focal pain suggests degeneration or torsion of a pedunculated fibroid. Ovarian cyst = pain from complications (torsion/rupture/haemorrhage) is the distinguishing feature. Ovarian cancer = systemic/constitutional symptoms + non-specific GI upset are classic; distension may be from ascites rather than the mass itself.
B. Physical Examination
Manner: professionalism, privacy, chaperone. [1]
- Vital signs, BMI and performance status
- Pallor (anaemia from menorrhagia or malignancy)
- Lymphadenopathy (metastatic disease — Virchow's node/left supraclavicular = Troisier's sign)
- Lower limbs — the slide photograph illustrates unilateral swelling: look for oedema and clinical features of DVT from venous compression or malignancy-associated thrombosis
- Systematic examination of cardiovascular, respiratory systems
Pregnancy testing belongs in the investigation pathway. Obtain urine or serum beta-hCG promptly in anyone of reproductive potential when pregnancy is possible, but do not delay resuscitation or life-saving treatment in an unstable patient.
Shape of abdomen; Mass (location, size, mobility, regular, consistency); Tenderness; Ascites. [1]
Key points from senior notes on abdominal mass assessment [5]:
- Can you get below it? A mass rising from the pelvis classically has an impalpable lower border: you cannot get below it. This bedside sign supports, but does not prove, pelvic origin.
- Mobility: A uterine mass may move with the cervix on bimanual examination and does not move with respiration. Fixity can reflect malignancy, inflammation, endometriosis or adhesions.
- Ascites: Test for shifting dullness. Ascites plus a pelvic mass raises malignancy risk, but is not diagnostic—benign Meigs' syndrome and non-gynaecological causes of ascites remain possible.
Lower genital tract → Uterus → Adnexal mass (size, tenderness, mobility, arising from pelvis) → Pouch of Douglas (nodularity, thickening, tenderness in endometriosis) → Rectal examination. [1]
| Pathology | Findings |
|---|---|
| Fibroid | Pallor?; Usually non-tender (except red degeneration); Symmetric/asymmetric/irregular; Firm mass arising from pelvis, rubbery consistency; Mass moved with the cervix. Special: pedunculated/subserosal fibroids, fibroid polyps |
| Ovarian cyst | Vital signs if in pain; Mobility, tenderness, peritoneal signs, consistency; Usually separated from uterus; Less mobile if adhesions/endometriosis; Usually no ascites; May not be palpable if small or soft. Special: complications, Meigs' syndrome |
| Ovarian cancer | General condition; Signs of metastasis (lymphadenopathy, DVT, pleural effusion, organomegaly, deposits in Pouch of Douglas); Ascites + abdominal/pelvic mass; Mobile/fixed non-tender mass arising from pelvis; Rectal exam |
Meigs' Syndrome — High Yield
Meigs' syndrome = ovarian fibroma (benign sex cord stromal tumour) + ascites + pleural effusion. It resolves completely after tumour removal. Important because it mimics ovarian cancer on presentation but is BENIGN. Don't confuse this with pseudo-Meigs' (any pelvic tumour + effusion).
Why does fibroid mass move with the cervix?
Because fibroids arise from the uterine myometrium. The cervix is the lower part of the uterus. When you push the cervix during bimanual exam, the entire uterus (and its fibroids) moves as one unit. An ovarian mass, being separate from the uterus, will NOT move with cervical excitation (unless adhered by endometriosis or malignancy).
Differential diagnoses for pelvic mass: [1]
| Category | Examples |
|---|---|
| Gynaecological | Uterine fibroid, adenomyosis; Pregnancy (undiagnosed, molar); Ovarian cyst, paraovarian cyst, hydrosalpinx; Malignancies: ovarian cancer, uterine sarcoma, metastatic |
| Gastrointestinal | Mesenteric cyst, tumour, hernia, diverticulum, dilated bowel |
| Urological | Distended bladder, diverticulum, pelvic kidney, transplanted kidney |
| Retroperitoneal | Sarcoma (usually not palpable) |
| Others | Pseudocyst, abscess |
Urgent DDx — Don't Miss These
Shock, severe pain or peritoneal signs require immediate ABC resuscitation and urgent gynaecological/surgical assessment. Exclude ectopic pregnancy, adnexal torsion, ruptured or haemorrhagic cyst, pelvic sepsis and non-gynaecological emergencies. Operative access is diagnosis- and stability-dependent: laparoscopy is often appropriate for torsion in a stable patient, while laparotomy may be required for major haemorrhage, a very large mass or suspected malignancy. [1]
Obtain a pregnancy test promptly when relevant, but never delay emergency resuscitation or operative control of bleeding.
D. Investigations and Pelvic Imaging
Pelvic ultrasound is a common investigation tool. [1]
| Investigation | When to Use | Why |
|---|---|---|
| Pelvic USS | First-line for all pelvic masses | Non-invasive, no radiation, excellent for characterising cystic vs. solid, uterine vs. adnexal |
| Pregnancy test | Promptly when pregnancy is possible | Identify intrauterine or ectopic pregnancy and guide safe investigation/management; do not delay emergency resuscitation |
| CBP | For menorrhagia | Assess degree of anaemia — guides urgency of management |
| CA-125 | Suspected ovarian cancer | Risk stratification (but low specificity — see below) |
| AFP, beta-hCG, LDH | Selected younger patients with suspected non-epithelial ovarian tumour | Helps identify germ-cell tumour patterns; NICE specifically recommends AFP and beta-hCG alongside CA-125 in suspected ovarian cancer under age 40 [16] |
| HE4 / ROMA | Selected adults with an adnexal mass already planned for surgery, using a validated assay and local pathway | Adjunct only; not screening, not stand-alone diagnosis and not a test to decide whether surgery is needed [17][18] |
| MRI pelvis | Ultrasound-indeterminate adnexal lesion; detailed fibroid/adenomyosis mapping when it will change management | Second-line tissue characterisation; not routine initial staging for suspected ovarian cancer [16][17] |
| CT abdomen/pelvis ± thorax | Ultrasound, CA-125 and clinical picture suggest ovarian cancer | Establish disease extent and support MDT/surgical planning [16] |
| PET-CT | Selected restaging, suspected recurrence or problem-solving after MDT review | Not routine initial cyst assessment or routine initial ovarian-cancer staging [17] |
| Pre-operative work-up | Before planned surgery | ECG, CXR, bloods, group & save |
The most appropriate initial imaging test for pelvic pain in a young patient is ultrasound of the pelvis. This was directly tested in 2025 MCQ Q1. [4]
i. Fibroids (Leiomyomas) — Detailed
Most common neoplasms of the uterus. Develops in 20-40% of reproductive age women. Benign smooth muscle tumour. Usually multiple causing asymmetrical enlargement of the uterus. Cause mass effect on the myometrium and surface lobularity. [1]
Why are fibroids so common? They are oestrogen- and progesterone-dependent tumours. This explains why:
- They grow during reproductive years (high oestrogen)
- They may enlarge during pregnancy (high oestrogen)
- They shrink after menopause (declining oestrogen)
- GnRH agonists (which create a pseudo-menopausal state) can shrink them
Types: 1. Intramural; 2. Subserosal; 3. Submucosal; 4. Pedunculated; 5. Intraligamentary; 6. Parasitic; 7. Cervical [1]
| Type | Location | Clinical Significance |
|---|---|---|
| Intramural | Within myometrium | Most common; causes menorrhagia and bulk symptoms |
| Subserosal | Outer surface of uterus | Causes pressure symptoms but less menorrhagia; can mimic ovarian mass |
| Submucosal | Protrudes into uterine cavity | Most likely to cause heavy menstrual bleeding (even when small) and subfertility; can be removed hysteroscopically |
| Pedunculated | On a stalk (subserosal or submucosal) | Can undergo torsion → acute pain; pedunculated subserosal can be confused with ovarian mass |
| Intraligamentary | Between layers of broad ligament | Can be difficult to remove surgically; can obstruct ureter |
| Parasitic | Detached from uterus with alternative blood supply | Rare; can be found anywhere in pelvis |
| Cervical | In the cervix | Can cause dystocia in pregnancy; may prolapse through os |
Transvaginal — for small fibroids. Transabdominal — for large fibroids. Well-circumscribed; Pseudocapsule from surrounding compressed myometrium. Hypoechoic / heterogeneous echoes. [1]
- Sonohysterogram (saline infusion sonography) is used to assess submucosal fibroids — it outlines the uterine cavity to show how much of the fibroid protrudes into it.
- On USS, fibroids typically look like well-defined, hypoechoic masses within the myometrium with posterior acoustic shadowing (especially if calcified).
How to read the lecture images (slides 28–32):
- The gross uterine specimen shows multiple rounded, pale nodules producing a lobulated external contour; a submucosal nodule projects toward the endometrial cavity, whereas subserosal nodules project outward.
- On transabdominal ultrasound, the full bladder is an anechoic acoustic window anterior to the uterus. Transvaginal ultrasound gives higher-resolution views of the myometrium and endometrial stripe.
- A fibroid is identified by continuity with the myometrium, a well-defined whorled or heterogeneous echotexture and often edge/refraction shadowing. Degeneration can make an otherwise solid fibroid look cystic or heterogeneous.
- In the sonohysterogram, instilled saline separates the endometrial surfaces and outlines the intracavitary component. This is the useful visual question: does the lesion distort the cavity? That affects bleeding, fertility and whether hysteroscopic treatment is feasible.
From radiology notes: a case of a 50/F with menorrhagia shows a uterine mass on transabdominal USS that is very vascular on Doppler — impression: leiomyoma. [6]
Degenerative changes: Hyaline, Myxoid, Calcific, Cystic, Hemorrhagic (red), Sarcomatous, Fatty [1]
| Degeneration | Mechanism & Clinical Relevance |
|---|---|
| Hyaline | Most common; replacement of muscle by hyaline tissue; usually asymptomatic |
| Myxoid | Gelatinous degeneration; can mimic malignancy on imaging |
| Calcific | Usually postmenopausal; visible on plain X-ray ("popcorn calcification") |
| Cystic | Follows hyaline/myxoid degeneration; creates fluid-filled spaces |
| Red (haemorrhagic) | Classically occurs in pregnancy when venous thrombosis and haemorrhagic infarction develop within a fibroid → acute pain and localised tenderness, sometimes with low-grade fever. Management is usually conservative after other emergencies have been excluded. |
| Leiomyosarcoma (important correction) | Not a degenerative change of a fibroid and usually arises de novo. It is rare and cannot be reliably excluded preoperatively; rapid growth alone is not a dependable diagnostic sign. New postmenopausal growth or atypical clinical/imaging features still warrant specialist assessment. [21] |
| Fatty | Rare; may be seen on CT |
Red Degeneration — Exam Favourite
Red degeneration is a classic cause of acute pain from a fibroid in pregnancy. It may present with localised uterine tenderness, low-grade fever and mild leukocytosis. Management is usually conservative after excluding obstetric and surgical emergencies: hydration, antiemesis and pregnancy-appropriate analgesia (paracetamol first-line; use NSAIDs only on obstetric advice because gestational-age restrictions apply). Surgery is not routine, but the diagnosis should be reassessed if the course is atypical or the patient is unstable.
ii. Adnexal Masses — Ovarian Cysts and Cancer
Types of benign ovarian masses: [1]
| Category | Entities |
|---|---|
| Functional | Follicular cyst, corpus luteal cyst, theca luteal cyst |
| Inflammatory | Endometriotic cyst, tuboovarian abscess |
| Germ cell | Mature teratoma (dermoid cyst) |
| Epithelial | Serous cystadenoma, mucinous cystadenoma, clear cell cystadenoma |
| Sex cord stromal | Fibroma, thecoma |
| Others | Ovarian ectopic |
Functional cysts are the most common ovarian cysts in premenopausal women. They arise from normal ovulatory physiology:
- Follicular cyst: A follicle fails to rupture or fails to regress → continues to fill with fluid → usually resolves spontaneously within 2-3 cycles
- Corpus luteal cyst: The corpus luteum fails to regress → can cause delayed menstruation (mimicking pregnancy) → may rupture causing haemoperitoneum
- Theca luteal cyst: Associated with high β-hCG levels (molar pregnancy, multiple pregnancy, ovarian hyperstimulation)
Endometriotic cyst (endometrioma / "chocolate cyst"): Contains old blood → ground glass appearance on USS → classic for endometriosis. DDx for dysmenorrhoea + subfertility + pelvic pain.
Mature teratoma (dermoid cyst): Contains tissues from all three germ layers (hair, teeth, sebum, thyroid tissue). USS shows mixed echogenicity, fat-fluid levels, Rokitansky nodule. X-ray may show teeth. Most common ovarian tumour in young women. Risk of torsion because of its weight. [6]
The lecture references a classification slide. The main categories are:
| Category | Subtypes | Key Features |
|---|---|---|
| Epithelial (~90% of ovarian cancers) | High-grade serous (most common), Low-grade serous, Mucinous, Endometrioid, Clear cell | Most are diagnosed late (Stage III/IV). BRCA1/2 mutations strongly associated with high-grade serous. |
| Germ cell | Dysgerminoma, Immature teratoma, Yolk sac tumour, Choriocarcinoma | Young women; good prognosis with chemotherapy; check AFP, β-hCG, LDH |
| Sex cord stromal | Granulosa cell tumour, Sertoli-Leydig cell tumour, Fibroma | May produce hormones (oestrogen → endometrial hyperplasia, androgens → virilisation) |
| Metastatic | Krukenberg tumour (from stomach/colon), breast, lymphoma | Bilateral, solid masses. Always exclude GI primary! |
Origin-based classification of malignant ovarian tumours: [1]
- Serous carcinoma can arise from the fallopian tube or the ovarian surface epithelium
- Endometrioid and clear cell carcinomas arise from endometriosis
- Mucinous carcinoma arises from inclusion cysts
- Sex cord stromal tumours (granulosa cell, Sertoli-Leydig) and germ cell tumours (dysgerminoma, yolk sac, immature teratoma) arise from their respective ovarian tissue compartments
Cyst content: [1]
- Anechoic (black) — simple fluid; most likely benign
- Low-level echoes — homogeneous low echogenicity; may be mucinous or haemorrhagic
- Ground glass appearance — homogeneous dense echoes; classic for endometrioma
- Hemorrhagic — thread-like fibrin strands; corpus luteal cyst or haemorrhagic cyst
- Mixed (heterogeneous) — as seen in teratoma
- Mixed with blood-fluid or fat-fluid level — teratoma
- Mixed (abscess) — tuboovarian abscess
| Slide pattern | What the image is showing | Interpretation guardrail |
|---|---|---|
| Normal ovary | Small anechoic follicles embedded in ovarian stroma | First prove ovarian origin; a separately seen normal ovary suggests an extra-ovarian lesion |
| Simple cyst | Anechoic content, smooth thin wall and posterior acoustic enhancement, without an internal vascular solid component | Reassuring morphology; management still depends on size, symptoms and menopausal status |
| Endometrioma pattern | Homogeneous low-level ground-glass echoes | Typical but not pathognomonic; a new vascular mural nodule or other atypical feature changes the risk assessment |
| Haemorrhagic cyst | Reticular/lacy fibrin strands or a retractile clot; the clot should not show internal Doppler flow | Can mimic a solid nodule on greyscale—Doppler and interval resolution help distinguish it |
| Mature teratoma | Mixed echogenic material, shadowing, echogenic lines/dots or a fat-fluid level | Fat-containing appearances are characteristic; torsion risk relates partly to lesion size/mobility |
| Tubo-ovarian abscess | Complex thick-walled multilocular mass with surrounding inflammatory change | Imaging overlaps with neoplasm; interpret with fever, inflammatory markers and PID history |
Use a standard lexicon rather than calling every heterogeneous lesion “malignant.” The current ACR O-RADS system builds on IOTA descriptors to assign a risk category and management recommendation. [19]
Unilocular-solid cyst → Multilocular cyst → Multilocular-solid cyst with papillary projection → Solid tumour [1]
The slide sequence is a morphology comparison, not a strictly monotonic ladder. A smooth multilocular cyst can still be benign, and some solid ovarian tumours are benign. Risk rises particularly with irregular solid tissue, vascular papillary projections, ascites or metastatic features. A simple unilocular anechoic lesion is reassuring, but no isolated descriptor substitutes for the complete clinical and ultrasound risk assessment.
Indicators of malignancy: Papillary projections ( > 3 mm in height); Solid-cystic masses; Strong intratumoral colour flow [1]
| Feature | Suggests Benign | Suggests Malignant |
|---|---|---|
| Walls | Thin, smooth | Thick, irregular |
| Septations | Thin ( < 3 mm) | Thick ( > 3 mm) |
| Content | Anechoic/ground glass | Solid components, mixed |
| Papillary projections | Absent | Present ( > 3 mm) |
| Doppler flow | Absent/peripheral | Strong intratumoral flow |
| Laterality | Unilateral | Bilateral |
| Ascites | Absent | Present |
The surgical photographs on slides 50–54 reinforce the same principle at gross level: a smooth, intact, thin-walled or uniformly solid mass is more reassuring than an irregular mass with surface excrescences, friable nodules, haemorrhage or necrosis. These are risk clues, not a histological diagnosis; definitive tumour type requires pathology.
Risk Stratification Tools
IOTA (International Ovarian Tumor Analysis) simple rules: [1]
- Classified MALIGNANT: at least 1 M feature and no B feature
- Classified BENIGN: at least 1 B feature and no M feature
- Inconclusive: if no B or M features present, or if both B and M features are present Sensitivity 95%, specificity 91%, positive likelihood ratio 10.37, negative likelihood ratio 0.06 [1]
IOTA B-rules (benign features):
- Unilocular cyst
- Solid component where largest solid component < 7 mm
- Acoustic shadows
- Smooth multilocular tumour < 100 mm
- No blood flow (colour score 1)
IOTA M-rules (malignant features):
- Irregular solid tumour
- Ascites
- At least 4 papillary structures
- Irregular multilocular-solid tumour ≥ 100 mm
- Very strong blood flow (colour score 4)
RMI I sensitivity 78% (95% CI 71-85%), specificity 87% (95% CI 83-91%) [1]
RMI = U × M × CA-125
Where:
- U = Ultrasound score: 0 points if 0 features; 1 point if 1 feature; 3 points if ≥2 features (features: multilocular, solid areas, bilateral, ascites, metastases)
- M = Menopausal status: 1 if premenopausal; 3 if postmenopausal
- CA-125 = serum level in U/mL
| RMI Score | Lecture-era triage bands (not universal management thresholds) |
|---|---|
| < 25 | Low risk |
| 25-250 | Moderate risk |
| > 250 | High risk in the cited validation protocol |
The validation study by Prys Davies et al. provides the following cancer risk estimates per RMI category: [1]
| RMI | Women (%) | Risk of Cancer (%) |
|---|---|---|
| < 25 | 40 | < 3 |
| 25–250 | 30 | 20 |
| > 250 | 30 | 75 |
This was tested in 2022 SAQ Q12(e): "Name the score to guide further management" → RMI [3]
RMI — Why the Formula Works
The RMI multiplies three independent risk factors: ultrasound features (morphology), menopausal status (baseline risk), and CA-125 (biomarker). Postmenopausal women get a higher multiplier (M=3) because any ovarian mass in a postmenopausal woman has a higher prior probability of malignancy (ovaries should be quiescent). This is also why CA-125 is more specific in postmenopausal women — fewer confounding causes of elevation.
RMI Thresholds Depend on the Pathway
Do not mix the lecture's research bands with referral thresholds. Current NICE CG122 refers an RMI I of 250 or more to the specialist MDT, whereas RCOG Green-top 34 uses 200 or more for postmenopausal ovarian cysts (and notes that some centres use 250). State the guideline/local pathway in an exam answer. [16][17]
Celomic epithelium related glycoprotein. Present in most serous, endometrioid, and clear cell ovarian carcinomas. Mucinous tumours express it less frequently. Also found in epithelium of fallopian tubes, endometrium, and uterine cervix. [1]
Usual lecture cut-off: 35 U/mL. Low specificity. More sensitive and specific in postmenopausal women. More useful in follow-up of patients after treatment for proven CA ovary and with elevated CA-125 level before treatment. [1]
The 35 U/mL value remains the conventional CA-125 threshold used in RMI and many secondary-care pathways. Primary-care thresholds may differ: NICE NG12 introduced age-specific CA-125 thresholds in April 2026. Follow the locally specified pathway rather than treating 35 U/mL as a universal diagnostic boundary. [16]
Causes of Elevated CA-125 (Exam Favourite!)
Elevated in: [1]
- Menstruating and pregnant women
- Benign ovarian tumours (10%)
- Endometriosis (20-30%)
- Acute PID
- Fibroids
- Liver cirrhosis (60-70%)
- Pancreatitis (30%)
- etc.
CA-125 — The Specificity Trap
CA-125 has low specificity, especially in premenopausal women. Benign explanations such as endometriosis, PID, menstruation and pregnancy are common. In contrast, in a postmenopausal woman with ascites and a complex adnexal mass, an elevated CA-125 is more concerning. The lecture explicitly states CA-125 is most useful for follow-up after treatment, not as a screening tool.
This was tested: 2022 SAQ Q12(b) asked for the most appropriate blood test in an ovarian-cancer vignette → CA-125 [3]. Clinically, however, CA-125 supports risk assessment; it does not confirm ovarian cancer without imaging and tissue diagnosis.
ROMA uses a predictive index (PI) combining HE4 and CA-125: [1]
- Premenopausal: PI = −12 + 2.38 × LN[HE4] + 0.0626 × LN[CA-125]
- Postmenopausal: PI = −8.09 + 1.04 × LN[HE4] + 0.732 × LN[CA-125] ROMA = exp(PI) / [1 + exp(PI)] × 100
| Premenopausal | Postmenopausal | |
|---|---|---|
| Low-risk | *** < 11.4%*** | *** < 29.9%*** |
| High-risk | ≥ 11.4% | ≥ 29.9% |
| Sensitivity in the lecture's cited dataset | 100.0% | 89.5% |
| Specificity in that dataset | 77.6% | 82.8% |
| PPV in that dataset | 15.0% | 57.6% |
| NPV in that dataset | 100.0% | 96.7% |
Why does ROMA include HE4? It combines HE4, CA-125 and menopausal status to estimate the likelihood of malignancy in a defined preoperative population. The formula and cut-offs are assay-specific, so use the validated laboratory implementation rather than hand-calculating from a slide.
The performance figures above belong to the lecture's cited cohort and are not universal guarantees. FDA-cleared intended use is as an adjunct in adults with an adnexal mass for which surgery is already planned, before oncology referral, alongside independent clinical and radiological assessment. It is not a screening test, stand-alone diagnostic assay or test for deciding whether surgery is required. RCOG also finds insufficient evidence for routine HE4/ROMA use in the initial assessment of postmenopausal cysts. [17][18]
ADNEX Model is referenced by the lecture as another risk stratification tool. [1]
The IOTA ADNEX model uses multiple ultrasound parameters plus CA-125 to provide probabilities for: benign, borderline, stage I cancer, stage II-IV cancer, and secondary metastatic cancer. It is available as an online calculator. Know that it exists and is more granular than RMI.
ADNEX model input parameters (from the lecture's worked example): [1]
- Oncology centre type (tertiary referral or not)
- Maximal diameter of the lesion (mm)
- Maximal diameter of the largest solid part (mm)
- Number of cystic locules (0–10 vs. > 10)
- Number of papillary projections (none / 1 / 2 / 3 / > 3; must be ≥ 3 mm)
- Acoustic shadow (yes/no)
- Ascites outside the pelvis (yes/no)
- Serum CA-125 (U/mL)
The model outputs a probability bar for each of the five categories. In the lecture's example (60 mm lesion, 20 mm solid component, 2 papillations, acoustic shadow present, ascites present, CA-125 = 500 U/mL): benign 48.6%, borderline 11.8%, stage I 5.0%, stage II–IV 32.4%, metastatic 2.2%. [1] The key visual lesson is that the combined malignant probability is 51.4%, even though “benign” is the largest single bar; interpret the full distribution, not only the tallest category.
| Modality | Role in Pelvic Mass |
|---|---|
| Pelvic USS | First-line for all pelvic masses |
| CT abdomen/pelvis ± chest | If clinical status, ultrasound and CA-125 suggest ovarian cancer: assess disease extent, including peritoneal/omental disease, nodes, liver and pleura; include thorax when clinically indicated or required by the local staging protocol [16] |
| MRI pelvis | Second-line characterisation when USS is indeterminate; useful for fibroid mapping and adenomyosis. NICE advises against routine MRI for initial suspected-ovarian-cancer assessment [16][17] |
| PET-CT | Selected restaging, recurrence assessment or treatment-response/problem-solving scenarios; not routine initial cyst assessment or routine initial ovarian-cancer staging [17] |
| Plain X-ray | May show calcified fibroid or teeth in dermoid cyst |
What the serial PET-CT panels show (slides 44–46): between the August and December studies, the pelvic and right-adnexal masses become smaller and less FDG-avid, illustrating a metabolic and anatomical treatment response. The subcarinal node changes little. Read PET and CT together: FDG uptake is not cancer-specific, and a fall in SUV is meaningful only in the clinical/treatment context.
From interventional radiology notes: uterine artery embolisation (UAE) is an IR procedure for fibroids — particles are injected into uterine arteries to devascularise fibroids, causing them to shrink. [8]
E. Management
Management principles: Review history, physical examination; Review investigation results, diagnosis, +/- previous treatment; Benign/malignant; acute/chronic; Presence of symptoms/signs; Patient's fitness; Patient's wishes; Individualised. [1]
Fibroids: [1]
- Asymptomatic — observation
- Symptomatic:
- a. Symptomatic relief: e.g., tranexamic acid (Transamin), Mirena IUS
- b. Surgical removal: myomectomy vs. hysterectomy; approach: open/laparoscopic/vaginal/hysteroscopic
- c. Other modalities: uterine artery embolisation (UAE), high-intensity focused ultrasound (HIFU)
Current practice individualises treatment by bleeding/bulk symptoms, fibroid size, number and location, cavity distortion, fertility goals, comorbidity and patient preference. For heavy menstrual bleeding with fibroids under 3 cm that do not distort the cavity, NICE considers LNG-IUS first-line; for larger fibroids, options include tranexamic acid/NSAIDs, hormonal therapy, UAE, myomectomy or hysterectomy. [20]
| Treatment | Indication | Key Points |
|---|---|---|
| Observation | Asymptomatic, small fibroids | Most fibroids don't need treatment; will shrink after menopause |
| Tranexamic acid | Menorrhagia | Antifibrinolytic — reduces bleeding by 40-50%; does NOT shrink fibroids |
| Mirena IUS | Heavy menstrual bleeding; also contraception | Reduces bleeding but does not remove fibroids; most suitable when the uterine cavity is not significantly distorted |
| GnRH agonists | Short-term pre-operative shrinkage or selected bridge therapy | Hypo-oestrogenic adverse effects and bone loss limit duration unless specialist add-back strategies are used; regrowth can occur after stopping |
| Myomectomy | Fertility preservation desired | Can be done laparoscopically, hysteroscopically (submucosal), or open; risk of recurrence |
| Hysterectomy | Definitive treatment; family complete | Total abdominal hysterectomy (TAH), laparoscopic, vaginal approach |
| UAE | Uterus-preserving alternative to surgery for selected patients | Interventional radiology procedure; discuss post-embolisation symptoms, reintervention and the uncertainty/trade-offs for future fertility and pregnancy |
| HIFU | Non-invasive; outpatient | Focused ultrasound ablation guided by MRI or USS; destroys fibroid tissue thermally |
HIFU Selection Criteria Shown in the Lecture [1]
These are lecture/local protocol criteria, not universal cut-offs. HIFU availability and eligibility depend on lesion position, acoustic window, MRI appearance, prior surgery, malignancy risk and local expertise.
| Indication: Uterine Fibroid | Indication: Adenomyosis |
|---|---|
| Symptomatic fibroids where surgical treatment would otherwise be advised | Significant symptoms related to adenomyosis, intractable to standard medical therapy, or patient considering UAE or surgery |
| Symptomatic fibroids but patient wishes to avoid surgery or is unwilling to receive blood transfusion | Localised adenomyotic lesion or adenomyoma < 10 cm on contrast-enhanced MRI, involving only anterior OR posterior wall (not both) |
| One dominant fibroid < 12 cm without significant necrosis on contrast-enhanced MRI; non-pedunculated; not suspicious of malignancy |
From 2018 SAQ Q11: A 46-year-old with heavy menstrual bleeding → physical exam focus (abdominal exam for mass, pelvic exam), investigations (CBP, pelvic USS, endometrial sampling), DDx (fibroid, adenomyosis), complications of hysterectomy (haemorrhage, infection, injury to ureter/bladder/bowel, VTE, vaginal vault prolapse). [2]
Hysterectomy Complications — Exam Must-Know
- Intraoperative: Haemorrhage, injury to bladder, ureter, or bowel
- Early postoperative: Infection (wound, pelvic, UTI), VTE, secondary haemorrhage
- Late: Vaginal vault prolapse, premature menopause (if ovaries removed), psychosexual issues
The slide's broad framework is observation for selected asymptomatic cysts, surgery for concerning/persistent lesions, and oncology referral when cancer is suspected. [1]
Current decision-making is more granular:
- First exclude pregnancy, ectopic pregnancy, torsion, rupture/haemorrhage and tubo-ovarian abscess when the presentation is acute.
- A small, classic physiologic follicle or corpus luteum generally needs no intervention. A classic haemorrhagic cyst may be followed to document resolution when size/menopausal status or diagnostic uncertainty warrants it.
- Symptoms do not automatically mean removal. Decide whether the cyst explains the symptoms and assess morphology, size, growth, torsion risk, haemodynamic status, age, fertility goals and malignancy risk.
- Persistence means the lesion is less likely to be physiologic, but does not by itself mandate oophorectomy. Options include expert ultrasound/MRI characterisation, surveillance or fertility-sparing cystectomy depending on the risk profile.
- Suspicious morphology or a high-risk model/clinical assessment warrants gynaecological-oncology referral before surgery, so staging and specimen retrieval can be planned without avoidable rupture.
The ACR O-RADS US v2022 framework is one current standardized route from ultrasound descriptor → risk category → management; apply the locally adopted system. [19]
The slides reproduce an older RCOG pathway. The December 2025 RCOG update is more conservative about surgery for simple cysts: [17]
- Simple, unilateral, unilocular cyst ≤3 cm: no routine follow-up is required.
- Asymptomatic, simple, unilateral, unilocular cyst > 3 to ≤5 cm with normal CA-125: repeat CA-125 and TVS (± TAS) in 4–6 months; discharge after 1 year if unchanged/reduced with normal CA-125, considering patient preference and surgical fitness.
- Symptoms, non-simple morphology, size > 5 cm, multilocularity, bilaterality, persistence with change, or raised risk: further evaluation and often surgery/MDT review—not automatic laparotomy for every lesion.
- Assess initially with CA-125 + transvaginal ultrasound, using transabdominal ultrasound as a supplement for large lesions. A normal CA-125 does not exclude cancer.
If low-risk surgery is chosen in a postmenopausal patient, RCOG generally recommends salpingo-oophorectomy rather than cystectomy, usually bilateral, with individualised counselling. This is not simply because “there is no fertility”: ovarian removal has endocrine and personal consequences, and the operative plan must reflect risk, age, comorbidity and patient preference.
Postmenopausal Ovarian Cyst Management Algorithm — Updated from the Slide [1][17]
Key points from the algorithm:
- The RMI threshold of 200 (rather than 250) is used in some guidelines to trigger CT staging and MDT referral
- A simple cyst ≤3 cm requires no routine follow-up under the 2025 RCOG update; the 4–6 month reassessment applies to selected > 3 to ≤5 cm cysts
- The lecture's 2016 flowchart depicts laparotomy/pelvic clearance after MDT review in selected higher-risk cases. Treat that as a historical pathway illustration; the definitive operation and access route are individualised by the specialist team.
Depends on stage and fitness of patients: [1]
- Early stage: surgery +/- chemotherapy
- Late stage: surgery AND chemotherapy +/- targeted therapy
Surgical principles for ovarian cancer:
- Staging surgery (early stage): comprehensive staging commonly includes peritoneal washings and inspection/biopsies, omentectomy and removal of the affected adnexa, with hysterectomy/contralateral salpingo-oophorectomy and nodal assessment determined by histology, stage and current specialist protocols. Fertility-sparing surgery may be appropriate for carefully selected patients after gynaecological-oncology counselling.
- Debulking/cytoreductive surgery (advanced stage): The objective is complete resection of all macroscopic disease, not merely leaving deposits under 1 cm. Operability, fitness and whether primary surgery or neoadjuvant chemotherapy is appropriate are specialist-MDT decisions. [16]
- Chemotherapy: Platinum-based (carboplatin) + paclitaxel is standard first-line
- Targeted/maintenance therapy: PARP inhibitors, bevacizumab and combinations are selected by histology, stage, response, BRCA/HRD status, prior therapy and the current local formulary—not automatically for every advanced cancer
Current NICE guidance offers pre-test counselling and germline testing to everyone with invasive epithelial ovarian cancer, not only patients with high-grade serous histology; the appropriate multigene panel depends on personal/family history and local genomic pathways. Results can guide therapy and cascade testing of relatives. [9][10][22]
From 2021 SAQ Q2: Applications of molecular genetic testing in gynaecological cancers — BRCA testing in ovarian cancer, MMR/MSI testing in endometrial cancer, FOXL2 in granulosa cell tumours, DICER1 in Sertoli-Leydig cell tumours. [11]
| Complication | Presentation | Management |
|---|---|---|
| Torsion | Sudden severe unilateral pelvic pain, often intermittent, with nausea/vomiting and adnexal tenderness; Doppler arterial flow does not exclude torsion | Time-sensitive diagnostic laparoscopy with detorsion and ovarian preservation whenever feasible; gross blue-black appearance alone does not prove non-viability. Oophorectomy is reserved for unavoidable tissue disintegration or another compelling indication [23] |
| Rupture | Sudden pain, may have haemoperitoneum and hypovolaemic shock | Supportive if haemodynamically stable; laparoscopy/laparotomy if significant bleeding |
| Haemorrhage (into cyst) | Acute pain, enlarging mass | Usually conservative; surgery if unstable |
| Infection | Fever, pelvic tenderness, purulent discharge | Antibiotics; drainage if tuboovarian abscess |
From 2024 MCQ Q13: Pelvic pain + 8 weeks amenorrhoea + heterogeneous mass separate from ovary + fluid in POD → this is an ectopic pregnancy scenario, not a simple ovarian cyst. The correct answer required serial βhCG and/or diagnostic laparoscopy depending on clinical stability. [12]
| Imaging | First-line? | Strengths | Limitations |
|---|---|---|---|
| Pelvic USS (TVS + TAS) | YES | No radiation, readily available, excellent for cyst characterisation, cheap | Operator-dependent, limited by body habitus, gas |
| Sonohysterogram | For submucosal pathology | Outlines uterine cavity with saline; excellent for submucosal fibroids/polyps | Invasive, requires patent cervix |
| MRI pelvis | Second-line | Superior soft tissue contrast, fibroid mapping, adenomyosis, indeterminate masses | Expensive, not always available, no real-time |
| CT abdomen/pelvis ± chest | Disease-extent assessment when ovarian cancer is suspected | Detects peritoneal/omental disease, nodes and distant disease | Radiation; not the best test for initial internal cyst morphology |
| PET-CT | Selected restaging/recurrence or response problem-solving | Functional + anatomical information | Not routine initial assessment/staging; radiation and inflammatory false positives |
| Plain X-ray (AXR) | Not routine | Can show calcified fibroid, teeth in dermoid | Low sensitivity |
Uterine fibroid, ovarian mass and cancer are important differential diagnoses of pelvic mass. History and physical examination usually help to suggest a diagnosis. Pelvic ultrasound is commonly performed. Management will depend on the age, symptom, condition and wish of the patient. [1]
High Yield Summary
-
Pelvic mass = Fibroid vs. Ovarian cyst vs. Ovarian cancer
- but always include pregnancy, gastrointestinal, urinary and retroperitoneal causes.
-
Test promptly when pregnancy is possible, while prioritising immediate resuscitation in an unstable patient.
-
Fibroid
- Most common uterine neoplasm. Firm, rubbery, moves with cervix. Heavy menstrual bleeding and bulk symptoms are common. USS: well-circumscribed, hypoechoic/heterogeneous, often with shadowing. Types: intramural, submucosal (cavity/bleeding effect), subserosal (bulk), pedunculated (torsion risk). Red degeneration can cause acute pain in pregnancy. Treatment is individualised: observation, bleeding control, medical shrinkage, myomectomy, hysterectomy, UAE or selected HIFU.
-
Ovarian cyst
- Many physiologic cysts resolve; follow-up depends on morphology, size, symptoms and menopausal status rather than a blanket 3–6 month rule.
- Complications = torsion, rupture, haemorrhage.
- Endometrioma = ground glass on USS.
- Dermoid = mixed echoes, fat-fluid level, teeth on X-ray.
- Postmenopausal simple unilateral unilocular cyst ≤3 cm: no routine follow-up under RCOG 2025; > 3 to ≤5 cm with normal CA-125 can usually be followed at 4–6 months.
-
Ovarian cancer
- May present with persistent non-specific GI symptoms, distension/ascites or weight loss. USS warning features include irregular solid tissue, vascular papillary projections and ascites. CA-125 supports risk assessment but is not diagnostic. Use IOTA/O-RADS, RMI or an adopted validated model; ROMA is a restricted preoperative adjunct, not screening. Management is specialist-MDT surgery/systemic therapy with biomarker-selected maintenance treatment.
-
Pelvic USS is generally the first-line imaging test for a suspected pelvic mass, with route (transabdominal/transvaginal) and further imaging tailored to the patient and suspected pathology.
Active Recall - Pelvic Mass, Ovarian Cancer & Cysts, Uterine Fibroids, Pelvic Imaging
[1] Lecture slides: GC 118. Pelvic mass ovarian cancer and cysts; uterine fibroid; pelvic imaging.pdf (all pages) [2] Past papers: 2018 Fourth Summative SAQ.pdf (Question 11) [3] Past papers: 2022 Fourth Summative SAQ.pdf (Question 12) [4] Past papers: 2025 Fourth Summative MCQ.pdf (Question 1) [5] Senior notes: Ryan Ho Fundamentals.pdf (p76-77, Approach to Palpable Mass) [6] Senior notes: Ryan Ho Radiology.pdf (p33, Pelvic imaging cases) [7] Senior notes: Ryan Ho Diagnostic Radiology.pdf (p74, PET-CT applications) [8] Lecture slides: IR 2025_VLau.pdf (p10, Interventional radiology for fibroids) [9] AOS material: AOS - Pathology.pdf (p20, Molecular genetic testing in gynaecological cancers) [10] Lecture slides: Molecular Pathology Seminar 7_Molecular genetic testing in gynaecological cancers_Sept 2023 Handout.pdf [11] Past papers: 2021 Fourth Summative SAQ.pdf (Question 2) [12] Past papers: 2024 Fourth Summative MCQ.pdf (Question 13) [15] ACOG: Dysmenorrhea — Painful Periods [16] NICE CG122/NG12: Ovarian cancer — recognition and initial management and suspected-cancer referral recommendations (updated April 2026) [17] RCOG Green-top Guideline No. 34: The Management of Ovarian Cysts in Postmenopausal Women (minor update December 2025) [18] US FDA: ROMA 510(k) decision summary and intended-use precautions [19] American College of Radiology: O-RADS US v2022 [20] NICE NG88: Heavy menstrual bleeding — assessment and management [21] ACOG Committee Opinion 822: Uterine Morcellation for Presumed Leiomyomas [22] NICE NG241: Ovarian cancer — identifying and managing familial and genetic risk [23] ACOG Committee Opinion 783: Adnexal Torsion in Adolescents
GC117 I Want To Have A Baby Male And Female Infertility
Male and female infertility refers to the inability of a couple to achieve pregnancy after 12 months of regular unprotected intercourse, resulting from disorders of sperm production or function, ovulatory dysfunction, tubal damage, uterine abnormalities, or unexplained factors in either partner.
GC119 Vaginal Discharge Obstetric And Gynaecological Infections
Vaginal discharge resulting from obstetric and gynaecological infections encompasses abnormal genital tract secretions caused by pathogens such as Candida, bacterial vaginosis organisms, Trichomonas, Chlamydia, or Neisseria gonorrhoeae during pregnancy or in the gynaecological setting, requiring prompt identification and treatment to prevent complications.