4.7 Ovary

Question 1

Ovarian volumes and ligaments

Answer 1

Volumes - 3 mL pre-menarche, 10 mL menstruating, 6 mL postmenopausal
Abnormal if >18 mL premenopausal or >8 mL postmenopausal
Ligaments
Mesovarium - ovary to posterior surface broad ligament
Ovarian ligament - ovary to uterus
Suspensory ligament - ovary to pelvic side wall

Question 2

Ovarian tumours - benign and malignant features

Answer 2

Benign features: 10 cm = 40% malignant

Question 3

Functional ovarian cysts

Answer 3

Follicular cyst (>25 mm, produce oestrogen, ±internal echoes; repeat US at 2 or 6 weeks)
Corpus luteum cyst (can be 5-10 cm, produce progesterone, bleeding into / failed resorption of corpus luteum, maximum size at 8-10 weeks in pregnancy, resolve at 16 weeks)
Theca lutein cysts (GTD, usually bilateral and multilocular, may measure up to 20 cm)

Question 4

Paraovarian cysts

Answer 4

Embryonic remnant in broad ligament; 10% of adnexal masses; must see ovary separately for diagnosis

Question 5

Peritoneal inclusion cysts

Answer 5

Nonneoplastic reactive mesothelial proliferations; extraovarian location with ‘spiderweb’ pattern of entrapped ovary only in premenopausal with hx PID / surgery; can also simulate hydrosalpinx and paraovarian cysts

Question 6

PCOS

Answer 6

Stein-Leventhal triad: Oligomenorrhoea, hirsutism, obesity
Hormones: Elevated LH and LH/FSH ratio, elevated androgens
Bilateral enlarged ovaries (similar size bilaterally) with >5 peripherally located cysts, each >5 mm, with a hyperechoic stroma
Hypoechoic ovary without individual cysts (25%), Normal ovary (25%)

Question 7

Benign ovarian tumour

Answer 7

Benign serous cystadenoma
Thin walled, uni- or multilocular, homogenous on CT and MR, no endo- or exocystic vegetations

Benign mucinous cystadenoma
Usually larger, almost always multilocular (varying density locules), smooth walls and septae

Question 8

Ovarian Ca and CA125

Answer 8

25% gynaecological malignancy, 65% metastatic at diagnosis; CA125 positive (>35) in 35% (early) - 80% (metastatic), but if mucinous

Question 9

Epithelial ovarian tumours

Answer 9

Malignant serous or mucinous cystadenocarcinoma (25%)
Serous 50% bilateral; Mucinous 25% bilateral

Endometroid carcinoma (10-15%)
30-50% bilateral; 15-30% association with endometrial cancer / hyperplasia

Clear cell carcinoma (5%)
Nearly all have previous endometriosis, often presents as large endometrioma with solid components

Brenner tumour (= transitional cell tumour)
Small, rarely malignant, 30% association with other ovarian tumours;
Multilocular cystic mass or small mostly solid mass ± enhancement of solid components
MR: low signal, CT: extensive amorphous calcification

Question 10

Germ cell tumours

Answer 10

Mature teratoma (commonest and only benign germ cell tumour)
Commonest benign ovarian tumour if <20 y/o, raised AFP)

Question 11

Sex-cord stromal tumours

Answer 11

Granulosa cell
Commonest oestrogen producing and sex-cord stromal tumour; usually peri-/postmenopausal; associated with endometrial polyps, hyperplasia and carcinoma (3-25%), 95% bilateral

Fibrothecoma
Arise from stroma, postmenopausal
Homogenous hypoechoic mass, posterior acoustic shadowing, delayed homogenous enhancement on CT with dense calcifications, Low signal on T1W and very low on T2W with scattered high signal (oedema / cystic degeneration)
Commonest sex cord tumour (fibroma, 4%; thecoma 1%), Lipid rich with oestrogenic activity; association with ascites and Meigs syndrome (unilateral pleural effusion)

Sclerosing stromal cell tumour
Benign, usually young women; large mass with solid and cystic components
Early peripheral enhancement with centripetal progression on dynamic studies

Sertoli and Leydig cell tumours (<0.5% ovarian neoplasms)
Low grade malignancy, usually young women, almost always unilateral commonest virilising tumour, heterologous tissue
Well defined solid enhancing mass with intratumoral cysts

Question 12

Metastatic ovarian tumours

Answer 12

10% of all ovarian tumours, occur during reproductive years
Commonest: Colorectal, stomach
Others: Breast, lung, contralateral ovary
Kruckenberg tumour: Mucin secreting signet ring cells, usually from GIT; shows bilateral complex masses with hypointense T1W solid components and int

Question 13

Ovarian tumours

Answer 13

1. Epithelial tumours (65%)
2. Germ cell tumours (15-20%) - elevated AFP and hCG if malignant
3. Sex-cord stromal tumours (8%)
4. Metastatic
   10% of all ovarian tumours, occur during reproductive years

Question 14

Staging ovarian cancer

Answer 14

I: Limited to ovary
II: Both ovaries ± ascites
III: Intraperitoneal metastases
IV: Extraperitoneal metastases

Question 15

Ovarian vein thrombosis

Answer 15

Rare cause of PE, right > left

Usually due to infection, hypercoaguable state, postpartum (especially if post Caesarian Section)