4. Gynaecology p73-86 (Ovaries and Misc)

Question 1

Ovaries - trivia (3)

Answer 1

Never biopsy or recommend biopsy of an ovary.
To find an ovary on CT, follow the gonadal vein.
Haemorrhage in a cystic mass usually means it’s benign.

Question 2

Ovulation (7)

Answer 2

Follicles seen during early menstrual cycle are usually small (<5mm).
By day 10, there’s usually one dominant follicle. By mid cycle, this is usually around 20mm, and contains a mature ovum.
LH surge causes dominant follicle to rupture, releasing the egg.
Follicle then regresses in size, forming Corpus Luteum.
Small amount of fluid can be seen in the cul-de-sac.
Occasionally, a follicle bleeds and re-expands (haemorrhagic cyst)

Question 3

Cumulus Oophorus (2)

Answer 3

Collection of cells in a mature dominant follicle that protrudes into the follicular cavity, and signals imminent ovulation.

Question 4

Clomiphene (2)

Answer 4

Fertility meds like this force maturation of multiple bilateral ovarian cysts.
Common to see multiple follicles at >20mm in diameter by mid cycle.

Question 5

Theca lutein cysts. (5)

Answer 5

Functional cyst related to overstimulation from b-HCG.
Large cysts 2-3cm and ovary with multilocular “spoke wheel” appearance.
Three main causes:
- Multifetal pregnancy
- Gestational trophoblastic disease (moles)
- Ovarian hyperstimulation syndrome

Question 6

Old vs Young ovaries (9)

Answer 6

Premenstrual:
- Ovaries of paediatric patient stay small until age 8-9. May contain small follicles.
Premenopausal:
- Premenopausal ovaries may be HOT on PET, depending on menstrual cycle.
- PET should be done in first week of cycle.
Postmenopausal:
- Considered abnormal if exceeding upper limit of normal, or twice the size of other ovary (even if no mass)
- Small cysts (<3cm) seen in 20% of women.
- Postmenopausal ovaries are generally atrophic, lack follicles and difficult to find on US.
- Ovarian volume decreases from 8cc at 40 to 1cc at 70. Max postmenopausal ovarian volume is 6cc.
- should NOT be hot on PET.

Question 7

Ovarian hyperstimulation syndrome (4)

Answer 7

Complication associated with fertility therapy (5% of cases).
Ovaries with theca lutein cysts, ascites and pleural effusions.
May also have pericardial effusions.
Complications include increased risk of overian torsion (big ovaries) and hypovolaemic shock

Question 8

Cyst in postmenopausal woman (4)

Answer 8

If simple, generally benign, however:
- >1cm gets yearly follow up
- Less than 5cm (still likely benign) gets 3-6 monthly follow up
- >7cm gets MRI
If seen on CT first, US needed to confirm totally cystic, without suspicious features like papillary projections, nodules, thick septations etc.

Question 9

Corpus luteum vs ectopic pregnancy (5)

Answer 9

Both can have ring of fire appearance.
Most ectopic pregnancies occur in the tube (corpus luteum is an ovarian structure).
Corpus luteum should move with the ovary, ectopic will move separately (can push the ectopic away from the ovary).
Tubal ring of ectopic pregnancy is more echogenic compared to ovarian parenchyma, whereas wall of corpus luteum is usually less echogenic.
Specific (not sensitive) finding in ectopic pregnancy is RI of <0.4 or >0.7.

Question 10

Benign ovarian masses - types (6)

Answer 10

Physiologic and functioning follicles.
Corpora lutea
Haemorrhagic cysts
Endometriomas
Benign cystic teratomas (dermoids)
Polycystic ovaries

Question 11

Corpus luteum (3)

Answer 11

Normal corpus luteum arises from a dominant follicle.
Can be large (5-6cm), with variable appearance.
Most common is solid and hypoechoic, with “ring of fire” (intense peripheral blood flow).

Question 12

Functioning ovarian cysts (5)

Answer 12

Affected by the menstrual cucle.
Usually <25mm in diameter, and will change or disappear in 6 weeks.
If cyst persists and doesn’t change or increase in size, considered a non-functioning cyst (not under hormonal control)
Simple cysts >7cm in size need surgical or MR evaluation, due to difficulty to completely evaluate them that big on US, and risk of torsion.

Question 13

Endometrioma (7)

Answer 13

Affects women of childbearing age, can cause chronic pelvic pain associated with menstruation.
Classically triad of infertility, dysmenorrhoea and dyspareunia.
Buzzword appearance is rounded mass with homogenous low level internal echoes and increased through transmission.
Fluid-fluid levels and internal septations can also be seen.
More unusual/varied the echogenicity and the more ovoid or irregular the shape, the more likely the mass is to be an endometrioma.
Endometriomas won’t change on follow up, whereas haemorrhagic cysts will.
Complications of endometriosis (bowel obstruction, infertility) are due to fibrotic reaction associated with the implant.
Most common location for solid endometriosis is uterosacral ligaments.

Question 14

Endometriomas and malignancy (4)

Answer 14

1% of endometriomas become malignant, usually endometrioid or clear cell carcinoma.
Malignancy is rare in endometriomas under 6cm.
Usually occurs in ones >9cm.
Majority of cases are older than 45.

Question 15

Endometrioma and pregnancy (3)

Answer 15

Decidualised endometriomas: solid nodule with blood flow in endometrioma of pregnant woman.
Mimic of malignancy, will get followed up.
If patient is not pregnant, a solid nodule with blood flow represents malignant degeneration.

Question 16

Endometrioma on MRI (3)

Answer 16

T1 bright (blood). Fat signal will not suppress (shows it’s not a teratoma).
T2 dark (from iron in endometrioma).
Shading sign is a buzzword on MR. T2 will show “shading” - T2 shortening (darkening) of a lesion that is T2 bright.

Question 17

Haemorrhagic cysts (4)

Answer 17

Ruptured follicle bleeds internally and re-expands, resulting in a homogenous mass with enhanced through transmission (tumour won’t do this), similar look to endometrioma.
Lacy “fishnet” appearance is sometimes seen, considered classic.
Doppler flow absent.
Haemorrhagic cyst will disappear in 1-2 menstrual cycles, whereas an endometrioma won’t.

Question 18

Haemorrhagic cyst on MRI (2)

Answer 18

T1 bright (blood), not fat suppressed (not teratoma).
Will NOT enhance.

Question 19

Haemorrhagic cyst in postmenopausal (2)

Answer 19

Postmenopausal women may occasionally ovulate. Follow up in 6-12 weeks.
Late postmenopausal women should NEVER have a haemorrhagic cyst, so if something looks like one, it’s cancer until proven otherwise.

Question 20

Dermoid (3)

Answer 20

Usually young women (20-30s), commonest ovarian neoplasm in under 20s.
Tip of the Iceberg sign: absorption of most of the US beam at the top of the mass.
Typical US appearance is cystic mass with hyperechoic solid mural nodule (Rokitansky nodule or dermoid plug).
Septatins seen in about 10%.

Question 21

Dermoid on MRI

Answer 21

T1 bright (from fat), fat suppresses.

Question 22

Dermoid and malignancy (2_

Answer 22

1% of dermoids become cancer (usually squamous).
Risk factors are size (>10cm) and age (>50).

Question 23

Polycystic ovarian syndrome (4)

Answer 23

Typically overweight girl with infertility, acne and hirsutism.
Imaging criteria
- Ten or more peripheral simple cysts (typically small <5mm)
- Usually characteristic ‘string of pearls’ appearance.
- Ovaries typically enlarged (>10cc), although in 30% of patients the ovaries have a normal volume.

Question 24

Ovarian cancer (5)

Answer 24

Ovarian cancers often present as complex, cystic masses.
Typically intra-ovarian (most extra-ovarian masses are benign).
The role of imaging is to distinguish benign from malignant.
Malignancy suggested by
- Unilateral (or bilateral) complex cystic adnexal masses with thich (>3mm) septations and papillary projections (nodule with blood flow).
- Solid adnexal masses with variable necrosis.

Question 25

Ovarian cancer - concerning features (3)

Answer 25

Multiple thick or thin septations
Nodule with flow
Solid nodules without flow
- Get MR to ensure not a dermoid plug

Question 26

Serous ovarian/Cystadenocarcinoma/Cystadenoma (5)

Answer 26

Serous tumours are commonest ovarian malignancy.
60% of serious tumours are benign, 15% borderline, rest are malignant.
Favour women of childbearing age, malignant ones tend to occur in older women.
Usually unilocular with few septations.
Frequently bilateral (especially if malignant).
Papillary projections are common finding, siggests malignancy.
Ascites suggests mets (70% have peritoneal involvement at time of diagnosis).

Question 27

Muconous ovarian cystadenocarcinoma (6)

Answer 27

Often large mass.
Typically multiloculated, septa are often thin.
Papillary projections are less common with serous tumours.
Low level echos (from mucin).
Can get pseudomyxoma peritonei, with scalloping along solid orgns.
Smoking is a risk factor (espeically mucinous types).

Question 28

Serous vs Mucinous (4)

Answer 28

Serous
- Unilocular (fewer septations)
- Papillary projections common
Mucinous
- Multi-locular (more septations)
- Papillary projections are less common

Question 29

Endometrioid ovarian cancer (4)

Answer 29

Second most common ovarian cancer (serous is number one, mucinous is 3)
Bilateral 15% of time.
25% of women will have concomitant endometrial cancer (endometrial is primary, ovarian is met).
Endometriomas can turn into endometriod cancer.

Question 30

Ovarian mass + endometrial thickening (2)

Answer 30

Can be endometrioid cancer (often has both endometrial Ca and ovarian Ca) or Granulosa-Theca Call tumour (produces oestrogen, causing endometrial hyperplasia)

Question 31

Big Masses differential - adults (3)

Answer 31

Ovarian masses (Mucinous and serous)
Desmoids
Sarcomas

Question 32

Fibroma/fibrothecoma (5)

Answer 32

Ovarian fibroma is a benign ovarian tumour, commonly in middle aged women.
Fibrothecoma/thecoma spectrum has similar histology. Very similar to fibroid.
US: Hypoechoic and solid.
MRI: T1 and T2 dark, band of T2 dark signal around the tumour on all planes.
Calcifications are rare

Question 33

Meigs syndrome (3)

Answer 33

Ascites, Pleural effusion, Benign ovarian tumour (commonly fibroma)

Question 34

Fibromatosis (5)

Answer 34

Tumour like enlargement of the ovaries due to fibrosis.
Usually affects women around 25YO.
Associated with omental fibrosis and sclerosing peritonitis.
Dark T1 and T2 signal, with “Black Garland sign” on T2.
Benign, sometimes managed with removal of ovaries.

Question 35

Brenner tumour (4)

Answer 35

Epithelial tumour of the ovary, seen in women in 50s-70s.
Fibrous and T2 dark.
Calcifications are common (80%)
Also known as Ovarian Transitional Cell Carcinoma

Question 36

Struma Ovarii (4)

Answer 36

Subtype of ovarian teratoma.
Multolocular, predominantly cystic mass with intensely enhancing solid component.
MRI: very low T2 signal in “cystic” areas (actually thick colloid).
They contain thyroid tissue, can rarely get hyperthyroidism.

Question 37

Mets to ovary (3)

Answer 37

10% of malignant ovarian tumours are mets.
Primary is commonly colon, gastric, breast, lung, contralateral ovary.
Most common appearance is bilateral solid tumours.
Krukenburg tumour is a metastatic tumour to the ovaries from the GI tract, usually stomach.

Question 38

Ovarian torsion (5)

Answer 38

Rotation of ovary around ovarian pedicle can result in venous and arterial obstruction.
Associated with mass (cyst or tumour).
Most constant finding is a large ovary (unilaterally large ovary >4cm).
Peripheral cysts and free fluid often seen.
Lack of arterial or venous flow, however the ovary has dual blood supply, so flow doesn’t rule out torsion unlike a testicle.

Question 39

Hydrosalpinx (5)

Answer 39

Thin (or thick if chronic) elongated tubular structure in the pelvis.
“Cogwheel appearance” - normal longitudinal folds of fallopian tube becomming thickened.
“String sign” - incomplete septae.
“Waist sign” = tubular mass with indentations of its opposing walls (helps differentiate hydrosalpinx from ovarian mass)
Several causes, including PID, endometriosis, tubal cancer, post hysterectomy (without oophorectomy) and tubal ligation.
Tubal torsion is a rare and late complication

Question 40

PID (5)

Answer 40

Infection or inflammation of the upper female genital tract.
Secondary to Gonorrhoea or Chlamydia.
US: Hydrosalpinx.
Margin of uterus may become ill defined (Indefinite uterus is a buzzword).
Later can get tubo-ovarian abscess or pelvic abscess.
Can get bowel or urinary tract inflammation.

Question 41

Paraovarian cyst (5)

Answer 41

Congenital remnant arising from Wolffian duct.
Account for 10-20% of adnexal masses.
Classically round or oval, simple in appearance, and don’t distort the adjacent ovary (key finding).
Can indent the ovary and mimic exophytic cyst.

Question 42

Ovarian vein thrombophlebitis (4)

Answer 42

Most common in post partum women, often with acute pelvic pain and fever.
80% occur on the right.
CT or US shows tubular structure with enhancing wall and low attenuation thrombus in the expected location of ovarian vein.
Can lead to pulmonary embolus.

Question 43

Peritoneal Inclusion cyst (8)

Answer 43

Inflammatory cyst of the peritoneal cavity, occurs when adhesions envelop an ovary.
Normal peritoneum can absorb fluid, adhesions cannot.
Normal secretions from actuve ovary, confined by adhesions, resulting on expanding pelvic mass.
Classic Hx is prior pelvis surgery, now with pain. Could say PID or endometriosis Hx.
US or MR with complex fluid collection, occupying pelvic recesses and containing the ovary.
Septations, loculations and particulate matter can occur within the contained fluid
Key features
- Lack of walls: passive shape that conforms to surrounding structures.
- Entrapment of an ovary, either in the collection or at the periphery.

Question 44

Gestational Trophoblastic disease (6)

Answer 44

Marked elevation of bHCG. Trend is useful to monitor tumour activity.
Often causes hyperemesis.
Often affects age >40, prior moles increase likelihood of another.
Types include
- Hydatiform mole
- Invasive mole
- Choriocarcinoma

Question 45

Hydatoform mole (3)

Answer 45

Most common trophoblastic disease, and benign.
Subtypes are complete mole or partial mole.
Theca lutein cysts are seen in molar pregnancies, most common in second trimester and are bilateral.

Question 46

Complete mole (classic mole) (6)

Answer 46

More common than partial.
Involves entire placenta, will be no fetus.
Diploid karyotype.
Pathogenesis is fertilization of an egg that has lost it’s chromosomes (46XX).
- First trimester US: uterus filled with echogenic, solid, highly vascular mass. Often described as Snowstorm appearance
- Second trimester US: vesicles that make up the mole enlarge into individual cysts (2-30mm), producing bunch of grapes appearance

Question 47

Partial mole (4)

Answer 47

Less common than complete, only involved part of placenta.
Triploid foetus, due to fertilisation of an ovum by 2 sperm (69XXY).
Lethal to the foetus.
- US: Placenta enlarged, areas of multiple diffuse anechoic lesions. May see fetal parts.

Question 48

Invasive mole (4)

Answer 48

Invasion of molar tissue into myometrium.
Typically seen after treatment of hydatiform mole (10% of cases).
US: echogenic tissue in myometrium.
MRI: Demonstrates muscle invasion better. Focal myometrial masses, dilated vessels and areas of haemorrhage and necrosis.

Question 49

Choriocarcinoma (6)

Answer 49

Aggressive malignancy which forms only trophoblasts, no villous structure.
Typical attacking pattern of choriocarcinoma is spreading locally (into myometrium and parametrium), then spread via blood to any site in the body.
Very vascular.
Classic scenario is serum bHCG rising in 8-10 weeks following evacuation of molar pregnancy.
US: Choriocarcinoma (at any site) results in highly echogenic solid mass
Rx: Methotrexate