Gyn Obs

Question 1

On a midline sagittal T2W MR image of the uterus of a 25-year-old female, the endometrium, junctional zone and outer myometrium of the corpus are clearly identified. From innermost to outermost, which of the following signal intensities best describes the normal uterus? [B4 Q89]

a. high, intermediate, low
b. high, low, intermediate
c. intermediate, high, low
d. intermediate, low, high
e. low, intermediate, high

Answer 1

b. high, low, intermediate

The premenopausal uterus normally has a bright endometrium within a dark junctional zone and an intermediate outer myometrium on T2W images. Cancer disrupts the zonal anatomy seen on T2W MRI. T1W sequences do not demonstrate uterine zonal anatomy.

On T2W images, the uterine cervix has a distinct zonal signal pattern that is particularly well seen on sequences acquired perpendicular to the long axis of the cervix. These are especially useful for cervical cancer staging.
The cervix lumen is bright
The cervical mucosa is intermediate to bright.
The fibromuscular cervical stroma is dark
The cervical stroma (outer layer) is intermediate

With age or radiation treatment, the uterus involutes and loses this zonal appearance on T2W MRI.

Question 2

Regarding normal pelvic floor anatomy, which of the following is contained within the middle compartment of the female pelvic floor? [B4 Q91]

a. bladder
b. urethra
c. vagina
d. rectum
e. anus

Answer 2

c. vagina

The pelvic floor is supported by the endopelvic fascia and the levator ani muscle complex. This complex consists of three muscle groups: iliococcygeal, pubococcygeal, and puborectalis. The anterior compartment of the female pelvic floor contains the bladder and urethra. The middle compartment contains the vagina, and the posterior compartment contains the rectum.

Question 3

A 25-year-old woman with a history of pelvic pain undergoes a transvaginal ultrasound examination. The endometrium is 15 mm thick. Which phase of the menstrual cycle is the patient in? [B5 Q10]

a. Proliferative phase
b. Day 7 after menstruation
c. Follicular phase
d. Luteal phase
e. Day 15 of the cycle

Answer 3

d. Luteal phase

Endometrial thickness:

• Immediately after menstruation: 1–4 mm thick.
• Proliferative phase: 7–10 mm.
• Follicular phase: 8–12 mm
• Luteal phase: 8–16 mm and becomes echogenic throughout.

Question 4

A 14-year-old female presents with a history of cyclic pelvic pain. Speculum vaginal examination reveals a bulging vaginal mass. An MRI of the pelvis demonstrates divergent uterine horns with a deep midline fundal cleft, two separate uterine cavities, two separate cervices, and a unilateral hemivaginal septum causing hematometrocolpos. There is associated renal agenesis on the side of the hemivaginal septum. What is the primary uterine anomaly?

a. Uterus didelphys
b. Uterine bicornuate bicollis
c. Septate uterus
d. Arcuate uterus
e. Imperforate hymen

Answer 4

a. Uterus didelphys

Uterus didelphys is caused by complete failure of fusion of the paramesonephric ducts, resulting in a completely duplicated system (two uterine cavities and two cervices) with no communication between the two cavities. It is associated with complete or partial vaginal septum in 75% of cases, which can result in obstruction and haematometrocolpos. Ipsilateral renal agenesis is associated with a vaginal septum.

Question 5

A 13-year-old girl presents with lower abdominal pain. She says she has had it intermittently for over a year. She has not yet had a period. On ultrasound examination the uterus is displaced cranially by a large cystic mass in the region of the vagina. It contains a large quantity of echogenic fluid, and a fluid-debris level is visible. The bladder is not visualised. What is the most likely diagnosis? [B2 Q49]

a. Duplication cyst
b. Rectovesical fistula
c. Haematocolpos
d. Hydrometra
e. Cloacal malformation

Answer 5

c. Haematocolpos

Haematocolpos is the accumulation of blood within the vagina and is typically caused by an imperforated hymen. This causes acute-on-chronic lower abdominal/pelvic pain as menstrual blood is prevented from normal discharge (apparent lack of menstruation). Ultrasound reveals an echogenic cystic mass with or without fluid-debris levels in the region of the vagina. The distended vagina often causes displacement of the uterus and compression of the bladder so that the latter may not be visualised.

Question 6

MRI shows two separate normal-sized uteri and cervices with a septum extending into the upper vagina. The two uteri are widely separated, with preservation of the endometrial and myometrial widths. What name is given to this abnormality? [B3 Q40]

a. Uterus didelphys
b. Mullerian agenesis
c. Unicornuate uterus
d. Uterus bicornuate
e. Septate uterus

Answer 6

a. Uterus didelphys

When partial fusion of the Müllerian ducts occurs, myometrium forms the dividing septum. This abnormality is known as a bicornuate uterus. A septate uterus arises when there is only partial resorption of the final fibrous septum dividing the two horns of the uterus. The latter defect results in further reproductive complications.

Question 7

A 17-year-old female with primary amenorrhoea is found on clinical examination to have a hypoplastic upper/middle vagina. MRI shows an absent uterus but normal tubes and ovaries. Which of the following is the most likely diagnosis? [B4 Q70]

a. uterus didelphys
b. unicornuate uterus
c. Mayer–Rokitansky–Kuster–Hauser syndrome
d. uterine agenesis
e. septate uterus

Answer 7

c. Mayer–Rokitansky–Kuster–Hauser syndrome

The uterus, fallopian tubes, and upper vagina arise from the paired paramesonephric (müllerian) ducts. The caudal parts fuse and ultimately form the uterus and upper vagina with resorption of the midline septum. The cranial parts remain unfused and form the fallopian tubes. Congenital uterine abnormalities arise with failure of development or fusion of this duct, or failure of midline resorption following fusion. Mayer–Rokitansky–Küster–Hauser syndrome describes uterine agenesis accompanied by hypoplastic proximal/middle third of the vagina but normal tubes and ovaries. Forty percent of patients with the syndrome have pelvic kidneys and other urinary tract anomalies are also associated.

Question 8

A 48-year-old woman undergoes investigation for postmenopausal bleeding. Ultrasound shows a hyperechoic endometrial mass which contains several small cystic spaces. Power Doppler reveals a vessel at its base. On T2-weighted MR imaging the mass contains a central fibrous core with low signal intensity and small, well delineated cysts showing marked high signal intensity. The central core enhances post-contrast administration. The junctional zone is intact. What is the most likely diagnosis? [B1 Q15]

a. Endometrial hyperplasia
b. Submucosal leiomyoma
c. Submucosal fibroid
d. Adenomyoma
e. Endometrial polyp

Answer 8

Endometrial polyp

Endometrial polyps are common benign tumours of the endometrial cavity. They are most common after the age of 40 years and are rare before menarche. Typical ultrasound appearance is of a hyperechoic endometrial mass which may or may not contain cystic spaces. A feeding vessel is often demonstrated from the base on power Doppler. (Submucosal fibroids are generally of reduced echogenicity).

On MRI, a mass which contains a central fibrous core that enhances post-contrast and also contains well-demarcated T2-hyperintense cysts suggests endometrial polyp. An intact junctional zone and smooth tumour-myometrium interface also favour a polyp.

Question 9

A 43-year-old woman with a history of breast carcinoma undergoes a CT of abdomen for abdominal pain and menorrhagia. This reveals an enlarged uterus, and she proceeds to MRI. The normal T2WI zonal anatomy of the uterus is preserved. The endometrial stripe is of high T2WI signal and measures 14 mm in diameter, and the myometrium is thickened. Lattice-like enhancement of the high-signal T2WI endometrial area is demonstrated on T1WI post contrast administration. There is no evidence of myometrial invasion. What is the diagnosis most consistent with these findings? [B1 Q61]

a. Intrauterine contraceptive device (IUCD)
b. Tamoxifen therapy
c. Lymphoma of the uterus
d. Endometrial stromal sarcoma
e. Pelvic congestion syndrome

Answer 9

Tamoxifen therapy

The normal endometrial stripe is of high T2WI signal and measures 3–6 mm in diameter in the follicular phase and 5–13 mm in the secretory phase. The description of the endometrium in this case is consistent with endometrial hyperplasia, but there is in addition myometrial enlargement. An enlarged uterus is frequently encountered in the presence of endogenous or exogenous hormonal abnormalities. In these cases, the uterus usually has normal zonal anatomy, although the signal intensity of the endometrium and myometrium is abnormally increased. However, with tamoxifen, the uterus can display marked zonal anatomy distortion. It is a weak oestrogen agonist and can result in endometrial hyperplasia, polyps, and carcinoma. The findings of multiple cysts or lattice-like enhancement of the endometrium post contrast are encountered frequently in relation to tamoxifen therapy and favour a benign diagnosis.

Question 10

A female undergoes transvaginal ultrasound for postmenopausal bleeding. In which of the following situations can you virtually exclude the presence of endometrial cancer? [B2 Q50]

a. An endometrial thickness of 5 mm in a patient who has never undergone hormone replacement therapy (HRT)
b. An endometrial thickness of 6 mm in a patient using sequential combined HRT
c. An endometrial thickness of 5 mm in a patient using continuous combined HRT
d. An endometrial thickness of 4 mm in a patient using sequential combined HRT
e. An endometrial thickness of 4 mm in a patient who has not used any form of HRT for one year or more

Answer 10

An endometrial thickness of 4 mm in a patient who has not used any form of HRT for one year or more

An endometrial thickness of 3 mm can be used to exclude endometrial cancer in women who:
1. Have never used HRT, or
2. Have not used any form of HRT for one year, or
3. Are using continuous combined HRT.

In the above conditions, the post-test risk of a patient having endometrial cancer is 0.6–0.8% when the endometrial thickness is 3 mm but 20–22% when the endometrial thickness is >3 mm.

An endometrial thickness of 5 mm can be used to exclude endometrial cancer in women using sequential combined HRT (or having used it within the past year). In this scenario, the post-test risk of a patient having endometrial cancer is 0.1–0.2% when the endometrial thickness is 5 mm but 2–5% when the endometrial thickness is >5 mm.

Question 11

A transvaginal ultrasound scan is performed on a premenopausal woman on day 21 of the menstrual cycle. Given that her endometrium is normal, which of the following measurements of endometrial thickness is most likely? [B4 Q65]

a. 2 mm
b. 2–4 mm
c. 4–8 mm
d. 7–14 mm
e. greater than 14 mm

Answer 11

7–14 mm

The menstrual endometrium is under 4 mm. After menstruation and up to day 14, the proliferative endometrium is 4–8 mm. Days 14–28 are secretory with the endometrium 7–14 mm. On ultrasound scan, the endometrium is seen as an echo-bright stripe. Unless the patient is taking tamoxifen or hormones, the postmenopausal endometrium should be less than 4 mm. A cut-off of 3 mm when performing screening for endometrial cancer has a 99% negative predictive value.

Question 12

A postmenopausal woman is found on MRI to have a multicystic adnexal mass that contains fluid–fluid levels and does not show any fat suppression. In addition, her uterus shows a widened junctional zone containing small bright foci on T2W images. For which of the following diseases is she most likely to be receiving oral treatment that can account for these findings? [B4 Q72]

a. urinary tract infection
b. deep venous thrombosis
c. endometrial cancer
d. breast cancer
e. bipolar disorder

Answer 12

Breast cancer

The patient is receiving tamoxifen. Side effects include subendometrial cysts, endometrial hyperplasia, and endometrial polyps. Less frequent side effects are endometriosis, polypoid endometriosis, adenomyosis and cervical polyps. There is an increased risk of endometrial carcinoma.

On MRI, an endometrioma can appear as a multicystic adnexal mass of high T1 - (blood) and both hypointense on T2 signal (iron - T2 Shading), but without the fat suppression that would be expected with a mature cystic teratoma.

Adenomyosis on MRI may manifest as a uterus with a thickened, low-signal, junctional zone on T2W images, containing small foci of high T2 signal.

Question 13

45-year-old woman presents with menorrhagia and dysmenorrhea. She has had three successful pregnancies and one therapeutic abortion in the past. She undergoes an MRI of the pelvis 14 days after the start of her last menstrual period. It reveals a junctional zone which measures 13 mm throughout, with hyperintense T2WI foci within it. With what conditions are these findings most consistent? [B1 Q2]

a. Endometrial hyperplasia.
b. Endometrial carcinoma stage 1A.
c. Pseudothickening.
d. Adenomyosis
e. Myometrial contraction

Answer 13

Adenomyosis

Adenomyosis appears as focal or diffuse thickening of the junctional zone of 12 mm or greater. Thickening of 8–12 mm is indeterminate, while thickening less than 8 mm usually allows exclusion of the disease. The bright foci on T2WI correspond to islands of ectopic endometrial tissue and cystic dilatation of glands and have been reported to be present in up to 50% of cases of adenomyosis. Occasionally haemorrhage within these areas of ectopic endometrial tissue can result in areas of high signal within the junctional zone on T1WI.

Question 14

A 30-year-old female patient with a history of infertility is referred for an HSG. She has a past history of pelvic inflammatory disease. HSG reveals multiple small outpouchings from the uterine cavity. What is the diagnosis? [B1 Q68]

a. Salpingitis isthmica nodosa
b. Asherman syndrome
c. Adenomyosis
d. Endometritis
e. Multiple endometrial polyps

Answer 14

Adenomyosis

This is a condition in which the endometrium extends into the myometrium in either a diffuse or a focal distribution. It generally manifests as pelvic pain or abnormal bleeding. It is more commonly detected on MR imaging as thickening of the junctional zone >12mm or on ultrasound as diffuse or focal heterogenous myometrium. On HSG, adenomyosis appears as small diverticula extending from the endometrial cavity into the myometrium.

Question 15

A 70-year-old woman is known to have uterine fibroids. There has been a clinically apparent increase in the uterine size. Transvaginal ultrasound appearances are in keeping with a large myometrial fibroid. Which of the following diagnoses must be considered in this patient? [B4 Q76]

a. lipo-leiomyoma
b. endometrial hyperplasia
c. adenomyoma
d. leiomyosarcoma
e. Bartholin’s gland tumour

Answer 15

Leiomyosarcoma

Uterine fibroids are estrogen-dependent and should involute following menopause. Increase in the size of a fibroid after menopause should raise the possibility of sarcomatous degeneration. On ultrasound scan, the appearance of leiomyosarcoma may be indistinguishable from that of a benign fibroid.

Question 16

Involvement of which of the following indicates the poorest prognosis in recurrent endometrial cancer? [B3 Q18]

A. Vagina
B. Spleen
C. Lung
D. Bladder
E. Well-differentiated tumour at original surgery

Answer 16

Spleen

Splenic, liver, and multiple sites of disease are independent predictors of poor outcome.

Question 17

Regarding endometrial carcinoma on MR: [B3 Q36]

A. Normal zonal anatomy is best demonstrated on T1
B. Tumour is typically higher signal compared with endometrial lining on T2
C. Tumour is typically higher signal intensity than myometrium
D. Enhances faster than myometrium on dynamic contrast enhancement
E. Usually low SI than brightly enhancing normal myometrial tissue after contrast

Answer 17

Usually low SI than brightly enhancing normal myometrial tissue after contrast

Endometrial tumours are usually isointense to myometrium on T1 and lower SI to endometrial lining on T2. Tumours demonstrate slower enhancement on DCE than myometrium. Normal zonal anatomy is clearly depicted on T2.

Question 18

A patient with endometrial cancer previously treated with surgery has an 18 FDG PET scan to look for recurrence. A false-negative result could be caused by which of the following scenarios? [B4 Q35]

a. peritoneal deposits smaller than 1 cm
b. bladder diverticulum
c. post-surgical inflammation
d. abscess
e. bowel avidity

Answer 18

Peritoneal deposits smaller than 1 cm

False positives can occur with PET because 18 FDG is a metabolic tracer, and activity is seen in normal bowel, ovaries (cyclical), endometrium (cyclical), blood vessels, bone marrow, and skeletal muscle. 18 FDG is renally excreted; hence, focal accumulation can be seen in ureters, bladder diverticula, pelvic kidneys, and urinary diversions. Benign processes can also take up this tracer, including abscesses, uterine fibroids, endometriosis, post-surgical inflammation, post-radiotherapy inflammation, and sacral fractures. False-negative PET scans can be caused by small tumour deposits close to the urinary bladder, where they cannot be resolved from each other.

Question 19

A 79-year-old female has a 6-month history of vaginal bleeding. Transvaginal ultrasound scan demonstrates an ill-defined endometrium measuring 20 mm in thickness. Outpatient clinic endometrial biopsy confirms endometrial adenocarcinoma. MRI stage is T4. Which of the following MRI features supports this stage? [B4 Q86]

a. disease limited to the endometrium
b. cancer invasion evident into the outer half of the myometrium
c. vaginal involvement
d. rectal serosal involvement
e. bladder mucosal involvement

Answer 19

Bladder mucosal involvement

Endometrial carcinoma becomes stage T4 when bladder or bowel mucosa is involved, whereas the stage remains T3 if other layers of bowel or bladder are invaded.

On MRI, endometrial carcinoma has homogeneous signal intensity, isointense to myometrium on T1W images, and hypointense to endometrial lining on T2W images. Endometrial cancers demonstrate slower contrast enhancement to a lower peak of enhancement than normal myometrium.

Question 20

A 65-year-old diabetic woman presents with bleeding per vagina. Ultrasound shows echogenic and irregular endometrium measuring 12 mm in thickness. What is the most likely diagnosis? [B5 Q12]

a. Submucosal fibroid
b. Endometrial polyp
c. Endometrial carcinoma
d. Endometrial sarcoma
e. Uterine sarcoma

Answer 20

Endometrial carcinoma

Endometrial carcinoma is the fourth most common female cancer, with a peak between 55 and 65 years. In postmenopausal women, endometrial thickness more than 5 mm should be investigated for endometrial carcinoma. Sarcomas are rare in this age group.

Question 21

A 36-year-old woman with a history of previous miscarriage treated by evacuation of retained products of conception, presents with amenorrhea. Hysterosalpingography shows multiple, irregular, constant filling defects in the uterine cavity which cannot be obscured by contrast filling into the uterine cavity. What is the most likely diagnosis? [B5 Q15]

a. Adenomyosis
b. Submucosal fibroids in uterus
c. Polyps
d. Asherman’s syndrome
e. Subserosal uterine fibroids

Answer 21

Asherman’s syndrome

Synechiae or intrauterine adhesions were described by Asherman and are usually a result of uterine curettage or evacuation of retained products of conception. The hysterosalpingogram findings are diagnostic.

Question 22

A 37-year-old woman presents with a watery vaginal discharge and attends for an MRI of pelvis. She becomes quite claustrophobic at the end of the scan, and you are called to assess her as she has been hyperventilating and the radiographers have become concerned. As you reassure her, you notice some peri-oral pigmentation. The MRI reveals a multi-cystic lesion (high T2WI and low T1WI signal) in the uterine cervix with a solid (low signal T1WI and T2WI) component in the deep cervical stroma. You note from the picture archiving and communication system (PACS) system that a barium enema previously revealed several colonic polyps. What is the likely cause for the MRI findings? [B1 Q66]

A. Malignant melanoma of the cervix.
B. Carcinoid tumour of the cervix.
C. Cervical pregnancy.
D. Minimal deviation adenocarcinoma of the cervix.
E. Invasive cervical squamous cell carcinoma.

Answer 22

Minimal deviation adenocarcinoma of the cervix.

This is also known as adenoma malignum and, as in this scenario, is often associated with Peutz Jeghers syndrome (characterized by mucocutaneous pigmentation, multiple hamartomatous polyps of the GI tract, and mucinous tumours of the ovary). Adenoma malignum makes up about 3% of adenocarcinoma of the cervix. Its MRI appearances are as described in the question, but the differential diagnosis includes deep nabothian cysts, florid endocervical hyperplasia, and even well-differentiated adenocarcinoma. It disseminates into the peritoneal cavity even in the early stage of the disease and its response to radiation or chemotherapy is poor.

Cervical squamous carcinoma makes up to 90% of cervical carcinoma. The tumour is of high signal compared to the hypointense cervical stroma, but not cystic as in our vignette. It advances predominantly by direct extension and local spread; haematogenous dissemination is only occasionally seen in the form of hepatic metastases.

Carcinoid tumour of the cervix is a subgroup of small cell carcinoma of the cervix. It cannot be differentiated from squamous cell carcinoma of the cervix on MRI findings.

Malignant melanoma of the female genital tract accounts for 1–5% of all melanomas. It usually occurs in the vaginal mucosa and occasionally involves the cervix. Malignant melanoma arising in the cervix is very rare (only about 30 reported cases). There is usually high signal intensity on T1WI.

The incidence of cervical pregnancy has been increasing, possibly due to the increased number of induced abortions. Reported risk factors include multiparity, prior cervical surgical manipulation, cervical or uterine leiomyomas, atrophic endometrium, and septate uterus. The major symptom is painless vaginal bleeding. At MR it is characterized by a mass with heterogeneous signal intensity and a partial or complete dark ring on T2WI sequences. As it contains haematoma, it often consists of some high signal on T1WI.

Question 23

A 48-year-old woman presents with shortness of breath and undergoes an HRCT of the chest to assess interstitial changes seen on plain film. She has emigrated from Eastern Europe and knows that she had a gynaecological cancer that was treated there but is unsure of her treatment. The HRCT reveals unilateral thickened interlobular septa, peri-lymphatic nodules, and ipsilateral hilar adenopathy. What is the most likely underlying diagnosis? [B1 Q67]

A. Cervical carcinoma.
B. Ovarian epithelial carcinoma.
C. Endometrial carcinoma.
D. Leiomyosarcoma of the uterus.
E. Vaginal carcinoma.

Answer 23

Cervical carcinoma.

This patient has developed lymphangitis carcinomatosis. In 50% of cases the septal thickening is focal or unilateral and this is useful in distinguishing lymphangitis from other causes of septal thickening, such as pulmonary oedema or sarcoidosis. Hilar adenopathy is present in 50% and pleural effusion in 30–50%. The interlobular septal thickening can be smooth (as in pulmonary oedema and alveolar proteinosis) or nodular (also found in sarcoidosis and silicosis).

Lymphangitis carcinomatosis usually occurs secondary to the spread of (adeno-) carcinoma, most commonly bronchogenic, breast, and stomach. The mnemonic Certain Cancers Spread By Plugging The Lymphatics (Cervix Colon Stomach Breast Pancreas Thyroid Larynx) is useful. Lymphangitis carcinomatosis is occasionally associated with cervical carcinoma and certainly more so than with the other options presented.

Question 24

A 42-year-old woman presents with post-coital bleeding. Transvaginal ultrasound shows the cervix to be enlarged, irregular and hypoechoic. MRI demonstrates a large cervical cancer with involvement of multiple pelvic lymph nodes. The left kidney is hydronephrotic. What is the most appropriate staging based on these findings? [B2 Q2]

a. T1
b. T2b
c. T3
d. T3b
e. T4

Answer 24

T3b

Cervical neoplasms are staged according to the TNM/FIGO classification. Stage I tumours are confined to the uterus. In stage IIA, there is involvement of the upper two-thirds of the vagina. Stage IIB shows parametrial invasion without pelvic sidewall involvement. Stage IIIA demonstrates invasion into the lower third of the vagina, and IIIB includes pelvic sidewall invasion with or without hydronephrosis. Tumour invasion into the bladder and rectal mucosa or distant metastasis accounts for stage IV disease. Pelvic nodal metastases do not alter the FIGO stage but para-aortic or inguinal node metastases are classified as stage IVB

Question 25

A 31-year-old woman presents with dysfunctional uterine bleeding. Transvaginal ultrasound shows a hypoechoic vascular mass in the cervix. The mass bulges into the endocervical canal and parametrium. On MRI, there is a cervical mass lesion which returns high signal on T2 and poorly defined margins beyond the cervical stroma. The most likely diagnosis is? [B5 Q6]

(a) Endometrial carcinoma
(b) Cervical carcinoma
(c) Focal adenomyosis
(d) Cervical lymphoma
(e) Prolapsed submucosal fibroid

Answer 25

Cervical carcinoma

Cervical carcinoma typically presents with bleeding and pelvic pain. MRI is the imaging of choice which shows high signal on T2 images.

Question 26

A 38-year-old woman presents with painless bleeding per-vagina. MRI shows a 2 cm lesion in the cervix, which is isointense on T1, hyperintense compared to cervical stroma on T2 and shows contrast enhancement. What is the most likely diagnosis? [B5 Q13]

(a) Prolapsed submucosal fibroid
(b) Cervical fibroid
(c) Cervical carcinoma
(d) Nabothian cyst
(e) Endometrial polyp

Answer 26

Cervical carcinoma

Cervical carcinoma is high signal as compared to fibrous cervical stroma on T2 and enhances with contrast.

Question 27

A 37-year-old woman was diagnosed with cervical carcinoma. MRI scan demonstrates a 4 cm tumour invading the upper third of the vagina and infiltrating the left parametrium. No other organ involvement is seen. What is the most accurate TNM staging for this tumour? [B5 Q34]

(a) T1b1
(b) T2
(c) T2b
(d) T3b
(e) T4

Answer 27

**Stage T2b **

Stage 1 lesions are confined to cervix. Stage 2a lesions involve the vagina, while 2b tumours invade the parametrium as well. Stage 3 lesions involve the lower third of vagina and/or the lateral pelvic wall. Stage 4 tumours are seen to invade other surrounding organs such as the bladder and rectum.

Question 28

A 40-year-old mother of two presents with a right lower abdominal lump near a surgical scar and with a cyclical history of pain. Ultrasound shows a 2 cm solid hypoechoic lesion in the subcutaneous tissue. Doppler shows internal vascularity. The most likely diagnosis is? [B5 Q5]

(a) Desmoid tumour
(b) Endometriosis
(c) Metastasis
(d) Lymph node
(e) Suture granuloma

Answer 28

Endometriosis

Endometriosis can be found in surgical scars or needle tracts. Most cases of subcutaneous endometriosis occur in Pfannenstiel incisions. Abdominal wall endometriosis is thought to occur in up to 1% of cases. Clinically it presents as a cyclical painful lump and can arise many years after surgery.

Question 29

A 43-year-old female presents with pelvic pain. On examination she is tender in the left iliac fossa and midline. Inflammatory markers are normal. A trans-abdominal ultrasound reveals a normal right ovary and uterus, but a 5.5-cm simple appearing cyst arising from the left ovary. As the reporting radiologist you: [B1 Q7]

A. refer to gynaecology for clinical assessment and serum Ca-125 measurement.
B. recommend trans-vaginal ultrasound.
C. recommend a repeat trans-abdominal ultrasound in 6 weeks’ time.
D. recommend MRI of pelvis.
E. issue a report stating that a benign simple cyst is seen to arise from the left ovary.

Answer 29

Recommend a repeat trans-abdominal ultrasound in 6 weeks’ time.

At ultrasound, a functional ovarian cyst is typically anechoic with a thin, smooth wall and posterior acoustic enhancement. Regardless of size, these cysts are unlikely to be malignant. A unilocular cyst greater than 3 cm in a premenopausal or greater than 5 cm in a postmenopausal female patient should be rescanned in approximately 6 weeks. Sonographic findings which increase the likelihood of malignancy include wall thickening, solid elements, septations, and abnormal blood flow. If a cyst displays any of these features or increases in size on interval scanning, further steps such as Ca-125 measurement or MRI may be warranted.

Question 30

An 80-year-old female is found incidentally to have a unilateral, unilocular, echo-free, thin-walled ovarian cyst of diameter 4 cm. There are no papillary projections or solid parts, and the CA-125 is less than 30 U/ml. Which of the following is the most appropriate management? [B4 Q73]

a. pelvic exenteration
b. total abdominal hysterectomy and bilateral salpingo-oophorectomy
c. bilateral oophorectomy
d. laparoscopic staging
e. repeat transvaginal ultrasound scan in 4 months

Answer 30

Repeat transvaginal ultrasound scan in 4 months

The Risk of Malignancy Index (RMI) is used to stratify the likelihood of an incidentally identified ovarian cyst being malignant. The RMI is the product of the ultrasound score, the CA-125 level and the score assigned according to menopausal status. Low-risk cysts can be managed conservatively. A cyst below 5cm in diameter that is unilocular, unilateral and echo-free, and has no solid parts or papillary formations has a risk of malignancy of less than 1%, and a 50% chance of resolving spontaneously in 3 months.

Question 31

A 26-year-old female patient is referred to the gynaecology team with a history of primary infertility and oligomenorrhoea. On examination she is hirsute and has a body mass index (BMI) of 31. Which of the following MRI findings are most consistent with her diagnosis? [B1 Q56]

A. High T2WI signal C-shaped cystic masses with thin, longitudinally oriented folds along their interior in both adnexae.
B. Multiple small peripheral rounded high T2WI signal areas with hypointense central stroma in both ovaries.
C. Normal ovaries.
D. A small ‘banana’-shaped uterus with a single fallopian tube.
E. A junctional zone of 14 mm with multiple hyperintense T2WI foci

Answer 31

Multiple small peripheral rounded high T2WI signal areas with hypointense central stroma in both ovaries.

The clinical features suggest polycystic ovarian syndrome (PCOS). The diagnosis is based on hormonal imbalance and patients often show an abnormality in the ratio of luteinizing hormone to follicle stimulating hormone. The MRI findings are those described, with multiple small peripheral cysts with low signal central stroma. MRI is not specific or sensitive, and 25% of patients with PCOS can have normal appearing ovaries. Multiple small, T2WI hyperintense cysts have been seen in patients with anovulation, medication-stimulated ovulation, or vaginal agenesis. The other descriptions are associated with infertility, but not particularly hirsutism or obesity. Option A describes bilateral hydrosalpinx. Option D describes a unicornuate uterus, which is associated with the poorest foetal survival among all uterine anomalies. Option E describes adenomyosis and using a junctional zone thickness of 12 mm or above optimizes the accuracy of MRI for this diagnosis.

Question 32

A female patient undergoes investigation for dysmenorrhea. She is obese, hirsute and has elevated luteinising hormone levels. Which of the following ultrasonographic findings is consistent with a diagnosis of polycystic ovarian syndrome? [B2 Q27]

a. Ovarian volume >10ml when no follicles measuring over 5mm in diameter are present
b. Ten or more follicles (3–12mm diameter) present in an ovary
c. Ovarian volume >15ml when no follicles measuring over 10mm in diameter are present
d. Twelve or more follicles (3mm diameter) present in an ovary
e. Ovarian volume >10ml when no follicles measuring over 10mm in diameter are present

Answer 32

Ovarian volume >10 ml when no follicles measuring over 10 mm in diameter are present

Diagnosis of polycystic ovary syndrome should not be made on imaging findings alone; clinical and biochemical studies must be obtained. The diagnosis can be supported when one or more of the following ultrasonographic features are demonstrated:

Radiopaedia:

1. Follicle number per ovary (FNPO) >20 or
2. Follicle number per section (FNPS) >10 or
3. Ovarian volume >10 ml when no corpora lutea or dominant follicles measuring over 10 mm in diameter are present.

If a follicle >10 mm is present, then the volume should be recalculated on a repeat scan when the ovary is quiescent to prevent overestimation of the ovarian volume.

Question 33

A 30-year-old, nulliparous woman with Stein–Leventhal syndrome is being treated for subfertility with clomiphene. She develops abdominal pain, distension, nausea, and vomiting. Ultrasound examination of the abdomen reveals both ovaries to be larger than 7 cm in length and packed with large follicles, and also reveals an ovarian cyst 12 cm in diameter. Ascites and a pleural effusion are also seen. What is the most likely diagnosis? [B4 Q61]

a. endometriosis
b. ovarian cyst torsion
c. ovarian hyperstimulation syndrome
d. ovarian serous cystadenoma
e. corpus luteum of menstruation

Answer 33

Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome is more commonly seen with human menopausal gonadotrophin therapy but can also be seen with clomiphene. Severe complications relate to volume depletion, such as hypovolaemia, oliguria, electrolyte imbalance and thromboembolic events. Intra-abdominal haemorrhage is also reported.

Question 34

A 28-year-old female is investigated for infertility. She has raised androgen levels and a higher-than-normal luteinizing hormone: follicle-stimulating hormone ratio. Pelvic ultrasound scan demonstrates bilaterally large ovaries with multiple small follicles. Which of the following is the most likely reason for the patient’s infertility? [B4 Q83]

a. cervical fibroids
b. hostile cervical mucus
c. ovarian torsion
d. polycystic ovarian disease
e. bilateral ovarian endometriosis implants

Answer 34

Polycystic ovarian disease

Polycystic ovarian disease is diagnosed by clinical, biochemical and ultrasound findings. Clinically, oligomenorrhoea, hirsutism and obesity are features. Luteinizing hormone is increased as is the luteinizing hormone: follicle-stimulating hormone ratio. Androgen levels are increased. Sonographic findings vary from normal-looking ovaries through hypoechoic ovaries without individual cysts to multiple, 5mm or more, peripherally located cysts in bilaterally large ovaries.

Question 35

A 35-year-old obese woman with history of irregular periods and hirsutism presents for ultrasound examination. A transvaginal ultrasound demonstrates bilateral enlarged ovaries with multiple hypoechoic cysts, ringed in the periphery of the ovaries measuring 5–10 mm in size. What is the most likely diagnosis? [B5 Q35]

(a) Endometriosis
(b) Stein–Leventhal syndrome
(c) Ovarian dermoids
(d) Tubo-ovarian abscesses
(e) Brenner tumours

Answer 35

Stein–Leventhal syndrome

Also known as polycystic ovary disease, patients may have reduced fertility, hirsutism, obesity, and menstrual irregularities. The ovaries are generally enlarged with multiple small follicles measuring less than 10 mm, usually subcapsular.

Question 36

A 28-year-old para 0 + 0 female patient is referred from the gynaecology team for an MRI of pelvis, after presenting with pain in the RIF. On TVUS they have identified enlargement of the right ovary and have raised the possibility of a mass. On MRI, a 2-cm ovoid lesion is demonstrated within the right ovary. It is of high signal on T1WI and T1WI fat saturation sequences, and low signal on T2WI sequences. There is no evidence of a mural nodule or ascites, and the uterus is not enlarged. What is the most likely diagnosis? [B1 Q75]
A. Fibro-thecoma.
B. Endometriotic cyst.
C. Brenner tumour.
D. Simple follicular cyst.
E. Endometroid carcinoma

Answer 36

Endometriotic cyst.
Also known as a chocolate cyst, the methaemoglobin within the lesion causes T1 shortening, resulting in increased signal on the T1WI sequence. This high signal remains and becomes more conspicuous on the T1WI with fat saturation sequence.
Endometriosis is characterized by the presence of tissue resembling endometrium outside the uterus. The ovaries are the most commonly involved site, and endometriotic cysts usually have a thick fibrotic wall with chocolate-coloured hemorrhagic material. An endometriotic cyst may be high or low signal on T2WI sequences. Chronic cyclical haemorrhage and increased viscosity of the cyst material will produce T2 shortening, leading to the low signal, or ‘T2 shading’. The patient usually presents with cyclical pain. The cysts have a propensity for multicentric growth and are often associated with fibrous adhesions. These latter features increase the MR sensitivity. Small peritoneal implants of endometriosis may be identified elsewhere and their conspicuity is increased by the use of fat saturation techniques.
Endometroid and clear cell carcinoma of the ovary are malignancies associated with endometriosis and these represent 17.5 and 7.4% of ovarian carcinomas, respectively. Chocolate cysts with multiple locules, mural foci, or nodules within the cyst are suspicious for malignancy and contrast should be administered if this appearance is seen.
The findings in this question are not consistent with a follicular cyst, which would show low T1WI and high T2WI signal.
Brenner tumours show low T2WI signal due to their abundant fibrous content and calcification, but also low T1WI signal. Fibro-thecomas show intermediate T1WI signal and usually low (although sometimes it can be mixed high and low) T2WI signal. They sometimes show associated uterine enlargement, as they may be oestrogenic.

Question 37

A 19-year-old female presents with vague lower abdominal pain. Ultrasound shows a right 5cm thin-walled unilocular ovarian cyst. Follow-up ultrasound six weeks later shows cyst regression. What is the most likely diagnosis? [B2 Q25]
a. Corpus luteum cyst
b. Endometrioma
c. Serous cystadenoma
d. Surface epithelial inclusion cyst
e. Follicular cyst

Answer 37

Follicular cyst
These are common ovarian masses that result from a failure of the mature Graafian follicle to rupture and release ova. Typically, they are smooth, thin walled, unilocular anechoic cysts that show spontaneous regression within four to six weeks. They may undergo haemorrhagic change producing internal echogenic material. They are generally larger than 2.5 cm and may occasionally grow up to 10 cm.

Question 38

On transvaginal ultrasound scan, an ovary measures 5 x 3 x 2 cm. Regarding the volume of this ovary, which of the following statements is most accurate? [B4 Q63]
a. it is large for pre- and postmenopausal ovaries
b. it is normal for pre- and postmenopausal ovaries
c. it is normal for a premenopausal ovary but large for a postmenopausal ovary
d. it is normal for a postmenopausal ovary but large for a premenopausal ovary
e. not enough information is given to assess the volume

Answer 38

It is normal for a premenopausal ovary but large for a postmenopausal ovary
Normal ovarian volume is less than 18cm³ before the menopause and less than 8cm³ postmenopausal. The volume can be estimated by multiplying the three diameters and dividing by two.

Question 39

A 23-year-old woman presents with recurrent cyclical lower abdominal pain. Ultrasound shows a 4 cm heterogenous cystic mass in the pelvis related to the left ovary. On MRI, the lesion has predominantly high signal on T1, T2 and STIR sequences. What is the most likely diagnosis? [B5 Q9]
(a) Metastasis
(b) Krukenberg tumour
(c) Ovarian dermoid
(d) Endometrioma
(e) Ectopic pregnancy

Answer 39

Endometrioma
MRI is highly sensitive and specific in the diagnosis of endometrioma. The endometrioma returns high signal on T1 and T2 and STIR sequences due to blood products.
On ultrasound the lesion may show diffuse homogenous low-level internal echoes (haemorrhagic debris). Other features may include septations or echogenic material suggesting a clot.

Question 40

Which of the following ovarian masses appear more cystic than solid? [B3 Q37]
A. Endometriosis
B. Metastases
C. Fibroma
D. Lymphoma
E. Arrhenoblastoma

Answer 40

Endometriosis
Cystadenocarcinoma, dermoid abscess, endometriosis and ectopic pregnancy are examples of cystic ovarian masses.

Question 41

Regarding mucinous ovarian tumours: [B3 Q45]
A. Are most commonly mucinous cystadenocarcinomas
B. Account for the most common benign epithelial neoplasias of the ovary
C. Are most common in the post-menopausal population
D. Rupture may lead to pseudomyxoma peritonei
E. When mucinous, cystadenomas are unilocular cysts with few septa

Answer 41

Rupture may lead to pseudomyxoma peritonei
20% of ovarian tumours are mucinous. These are the second most common benign epithelial neoplasm after serous ovarian neoplasia. Mucinous cystadenomas account for 80% and are multiloculated cysts with numerous septae, occurring in the third to fifth decades.

Question 42

A postmenopausal patient has a hysterectomy and bilateral salpingo-oophorectomy for bilateral ovarian masses. Histological examination confirms bilateral ovarian tumours and reveals concomitant endometrial adenocarcinoma. What is the most likely histological diagnosis of the ovarian lesions? [B4 Q13]
a. benign serous cystadenoma
b. benign mucinous cystadenoma
c. malignant serous cystadenocarcinoma
d. malignant mucinous cystadenocarcinoma
e. endometrioid tumour

Answer 42

Endometroid tumour
Benign serous cystadenoma is bilateral in 20% of cases, benign mucinous cystadenoma in 5%, malignant serous cystadenocarcinoma in 50% and malignant mucinous cystadenocarcinoma in 25%.

Endometrioid ovarian tumours frequently bilateral (30–50%) but they are also often (30%) found with concomitant endometrial adenocarcinoma.

Question 43

A 65-year-old female with biopsy-proven ovarian cancer has a staging CT scan. It reveals a left basal pleural effusion that after aspiration contains no malignant cytology. There is a large, complex, abdominopelvic mass, with ascites and peritoneal deposits outside the pelvis measuring over 2 cm in diameter. Pelvic and para-aortic lymph nodes are enlarged. There are liver surface and parenchymal deposits. Which of the described features results in a classification of stage IV disease? [B4 Q25]
a. ascites
b. pleural effusion
c. liver surface deposits
d. liver parenchymal deposits
e. 2 cm deposits outside the pelvis

Answer 43

Liver parenchymal deposits

Liver capsule deposits are stage T3/III. The pleural effusion cannot be regarded as M1/IV, because it requires positive cytology for this. Any involved regional nodes give stage IIIc and include obturator, common, internal and external iliac, laterosacral, inguinal and para-aortic.

Question 44

A postmenopausal patient is investigated for ascites. Cytology from the ascites reveals cells in keeping with an epithelial ovarian malignancy. Which of the following is the most appropriate staging investigation? [B4 Q47]
a. CT of the abdomen and pelvis with oral and intravenous contrast
b. CT of the chest, abdomen and pelvis with oral and intravenous contrast
c. MRI of the pelvis
d. 18FDG PET
e. PET/CT

Answer 44

CT of the abdomen and pelvis with oral and IV contrast

Plain chest radiograph may be added to this as a routine, but chest CT would be requested only with an additional reason to do so. MRI of the ovaries can be helpful in characterizing ovarian masses where ultrasound scan and CA-125 are equivocal. There may be a role for PET/CT in defining disease extent, but cystic tumour deposits, particularly when they may be on or close to bowel or associated with ascites, present a challenge for this technique.

Question 45

A 68-year-old female patient has a pelvic ultrasound scan for a palpable mass. Arising within the left ovary is a 15 cm cyst with an irregular thick wall, frond-like solid elements, multiple septations over 2 mm thick and a pulsatility index of 0.5. These sonographic appearances are most in keeping with which of the following ovarian cystic structures? [B4 Q69]
a. corpus luteum cyst
b. follicular cyst
c. polycystic ovaries
d. benign ovarian neoplasm
e. malignant ovarian neoplasm

Answer 45

Malignant Ovarian Neoplasm

Features of an ovarian cyst that suggest malignancy are thick irregular walls and thick septations (>2mm), large overall size, solid elements and, on Doppler scan, a high peak systolic velocity and low-impedance diastolic flow. Together, these give a resistive index (RI) of <0.4 and a pulsatility index (PI) of <1.

Question 46

A 60-year-old woman presents with progressive abdominal swelling. Ultrasound shows a large loculated cystic lesion in the lower abdomen, arising from the pelvis. Transvaginal scan shows a right-side complex mass in the adnexa with cystic and solid components. The solid components show blood flow with a low-resistive index. What is the most likely diagnosis? [B5 Q14]
(a) Ovarian dermoid
(b) Endometrioma
(c) Ovarian carcinoma
(d) Tubo-ovarian abscess
(e) Mature teratoma

Answer 46

Ovarian carcinoma

Malignant ovarian tumours commonly have solid and cystic components. The solid component has neovascularisation demonstrating a characteristic waveform with a low resistive index.

Question 47

A 50-year-old woman presents with pelvic pain and abdominal fullness. Ultrasound reveals ascites and a large hypoechoic ovarian mass with posterior acoustic enhancement. CT demonstrates a well-defined solid pelvic mass which shows poor contrast enhancement. There is also a right-sided pleural effusion. Follow-up imaging postsurgical resection shows no residual tumour and resolution of ascites. What is the most likely diagnosis? [B2 Q3]
a. Serous cystadenocarcinoma
b. Mucinous cystadenocarcinoma
c. Ovarian fibroma
d. Brenner tumour
e. Massive ovarian oedema

Answer 47

Ovarian fibroma

The condition described is Meigs syndrome. This occurs in about 1% of ovarian fibromas but is characterised by a large fibroma, ascites and a pleural effusion (typically right-sided). Ascites and effusion resolve after tumour resection.

Fibromas are benign stromal tumours composed of fibrous tissue. On ultrasound they are typically solid hypoechoic lesions with posterior acoustic enhancement.

Question 48

A five-year-old girl presents with atypical genital bleeding, breast development and pubic hair growth. T2-weighted MR imaging demonstrates a large solid mass with high signal intensity and an enlarged uterus with thick endometrium. Ascites is also present. Post-gadolinium T1-weighted imaging shows homogeneous tumour enhancement. What is the most likely diagnosis? [B2 Q38]
a. Immature teratoma
b. Sertoli–Leydig cell tumour
c. Thecoma
d. Sclerosing stromal tumour
e. Granulosa cell tumour

Answer 48

Granulosa cell tumour

Granulosa cell tumours are the most common ovarian tumours with oestrogenic manifestations that are classified as sex-cord-stromal tumours. They are subdivided into adult and juvenile types. The juvenile form affects prepubertal children and causes pseudoprecocity. In about a third of cases Sertoli–Leydig cell tumours cause virilisation. Thecomas are oestrogen-producing tumours but more than 80% occur in postmenopausal women. Immature teratomas are extremely rare but do occur in children. Elevated alpha-fetoprotein is found in up to 65% of cases. Sclerosing stromal tumours usually affect women younger than 30 years of age and a few cases have shown androgenic or oestrogenic manifestations. They are also known as hypervascular tumours which show early peripheral enhancement with centripetal progression.

Question 49

Granulosa cell ovarian tumour is diagnosed following removal of a complex pelvic mass. Which is the single best answer? [B3 Q10]
A. Account for 15% of ovarian tumours
B. The juvenile subtype is more common
C. Has a rapid rate of growth
D. Recurrent disease is almost always in the first two years after treatment
E. Variable imaging appearances are recognised from uniloculated cystic masses to solid masses

Answer 49

Variable imaging appearances are recognized from uniloculated cystic masses to solid masses

Represent 70% of malignant sex cord stromal tumours, but only 2-5% of all ovarian tumours have an unpredictable and indolent course with relapse occurring up to several years after initial diagnosis. The adult subtype accounts for 95% of all GCTs.

Question 50

Regarding ovarian fibromas: [B3 Q46]
A. Demonstrate rapid enhancement on CECT
B. Commonly present as Meigs’ syndrome
C. Are usually bilateral
D. Usually hyperechoic on ultrasound
E. Low on T1 and T2, less or equal to myometrium

Answer 50

Commonly present as Meigs’ syndrome

Question 51

A 36-year-old woman undergoes MRI of the pelvis for assessment of pelvic pain. She had a previous hysterectomy due to post-partum haemorrhage and thus transvaginal ultrasound (TVUS) is not an option. Abdominal ultrasound is technically difficult due to body habitus and the ovaries cannot be visualized. MRI reveals a 7-cm left adnexal lesion of predominantly intermediate and high signal on T2WI, but with low-signal components within. On T1WI, there is layering of low and high signal, with suppression of the high signal on the T1WI with fat saturation. What do you advise in your report? [B1 Q16]
A. Referral for chemoradiotherapy.
B. Referral for laparoscopy for staging.
C. Follow up in 3 months’ time.
D. Referral for surgery.
E. No follow-up required.

Answer 51

Referral for surgery. The findings are consistent with a mature cystic teratoma or dermoid cyst. They are derived from all three germ cell layers and thus contain fat and may contain desquamated epithelium, skin, hair, and teeth. The classical finding is of high T1WI signal, which suppresses on fat saturation imaging. They can often have a fat–fluid level. The low signal on T2WI may represent tooth or calcification.
Soft-tissue protuberances represent Rokintansky nodules or ‘dermoid plugs’ of sebaceous material. Dermoids can be bilateral in 8–25% of cases. The chance of malignant transformation is low, but surgical resection is indicated not just for relief of symptoms, but because of the risk of torsion (in 4–16% of cases) or rupture (rare but can lead to chemical peritonitis). Adjuvant treatment need not be considered unless the case is complicated by malignant transformation.

Question 52

A 28-year-old woman presents with a dull ache in her pelvis. Ultrasound shows a 7cm well-defined ovarian cyst. A distinct echogenic nodule which causes dense acoustic shadowing is seen projecting into the cyst’s lumen. What is the most likely diagnosis? [B2 Q13]

a. Mature cystic teratoma
b. Tubo-ovarian abscess
c. Endometrioma
d. Ovarian carcinoma
e. Corpus luteum cyst

Answer 52

Mature cystic teratoma Mature cystic teratomas (dermoid cysts) account for approximately 15% of all ovarian tumours. They are benign germ cell tumours containing tissues from all three germ cell layers. They most commonly present in younger women of reproductive age (20–40 years) and may be bilateral in up to 25%. They are generally cystic masses that may contain a pathognomonic distinct hyperechoic mural nodule (dermoid plug/Rokitansky nodule) which project into the cystic lumen and causes posterior acoustic shadowing. This nodule represents in-growth of solid tissue such as hair or teeth from the tumour wall.

Question 53

Regarding yolk sac tumours of ovary: [B3 Q6]
A. Are the most common malignant germ cell tumour of the ovary
B. Account for 5% of all ovarian malignancy
C. Carry a poorer prognosis than any other ovarian germ cell tumour
D. Haemorrhagic change is very rare
E. Are slow growing tumours

Answer 53

Carry a poorer prognosis than any other ovarian germ cell tumour
Yolk sac tumours are well-enhanced tumours consisting of mixed solid and cystic tissue with some area of haemorrhage. A ‘bright dot’ sign is recognized; a well-enhanced dilated vessel on the post-contrast image. Yolk sac tumours have a poor prognosis. They account for 1% of ovarian malignancies. They are the second most common malignant germ cell tumour after dysgerminomas.

Question 54

A 30-year-old woman has a well-circumscribed, cystic, adnexal mass with areas of dense focal calcification, small enhancing soft-tissue elements, fluid–fluid levels and bright regions on T1W MRI that become dark on fat-saturated sequences. Which of the following pathologies is most likely? [B4 Q3]
a,. Ovarian cyst with proteinaceous contents
b. Endometrioma
c. Mature cystic teratoma of the ovary
d. Ovarian cyst adenofibroma
e. Ovarian adenocarcinoma

Answer 54

Mature cystic teratoma of the ovary
The main differentials for an ovarian mature cystic teratoma (dermoid cyst) are endometriomas and proteinaceous ovarian cysts, which can also have fluid–fluid levels. Fat is frequently demonstrated in a dermoid cyst, but not in these differentials. Fat can be proven by a significant negative attenuation value on CT, or on MRI with chemical shift artefact in the frequency-encoding direction, a gradient echo sequence in which fat and water are in opposite phase or frequency-selective fat saturation sequences. Mature cystic teratoma contains mature tissues of germ cell (pleuripotent) origin. At least two of the three germlines should be represented. Mean patient age is 30 years, younger than for epithelial ovarian neoplasms, and it is the commonest ovarian mass in children. Usually asymptomatic, they can cause abdominal pain or other nonspecific symptoms. They are bilateral in 10% of cases.

Question 55

A 50-year-old woman presents with intermittent pelvic pain. Ultrasound shows a cystic mass in the adnexa. This contains a hyperechoic nodule which produces marked acoustic shadowing. CT shows a fat-containing lesion in the pelvis with a fluid level and a small, calcified nodule. What is the most likely diagnosis? [B5 Q2]

(a) Ovarian dermoid
(b) Liposarcoma
(c) Tubo-ovarian abscess
(d) Endometrioma
(e) Haemorrhagic ovarian cyst

Answer 55

Ovarian dermoid
This is a germ cell tumour which contains skin and dermal appendages. These are diagnosed by characteristic ectodermal contents of hair, teeth fat and bone. Identification of a sebum-fluid level and calcification is diagnostic. There is risk of malignant degeneration, torsion, and rupture.

Question 56

A 37-year-old woman presents with menstrual irregularities. Ultrasound shows a right adnexal abnormality. MRI shows a 3 cm well-defined lesion in the right adnexa which returns high signal on T1. What is the most likely diagnosis? [B5 Q42]
(a) Fibroma
(b) Brenner tumour
(c) Ovarian dermoid
(d) Pedunculated leiomyoma
(e) Fibrothecoma

Answer 56

Ovarian dermoid
Fibrous lesions in the adnexa are of low signal intensity on MRI. Ovarian dermoids return high signal because of their fat content, with signal drop-out on fat suppression images. Other causes of lesions which may return high signal on T1 include endometrioma, mucinous cystic neoplasm, haemorrhagic cysts, and ovarian carcinoma.

Question 57

A 45-year-old woman presents with anorexia and loss of weight. A CT of abdomen reveals bilateral non-calcified ovarian masses, but no ascites and no significant pelvic lymphadenopathy or peritoneal disease. Serum alpha fetoprotein, beta human chorionic gonadotrophin (b-HCG), and CA-125 are normal. The gynaecology team request an MRI of pelvis. This reveals that both ovaries are enlarged, the left more than the right. Bilateral cystic masses with low signal on T2WI/intermediate signal T1WI with solid portions are demonstrated. Gadolinium-enhanced T1WI with fat saturation reveals marked enhancement of these solid components and septa. What is the most likely diagnosis? [B1 Q40]
A. Krukenberg tumours.
B. Sertoli–Leydig tumours.
C. Dysgerminomas.
D. Fibromas.
E. Endodermal sinus tumours

Answer 57

Krukenberg tumours.
The history points towards a GI source, namely gastric carcinoma. Approximately 5–15% of ovarian tumours are metastatic lesions. They are bilateral in 75% of cases. They are often asymptomatic and may present before the primary tumour. They should be considered, along with serous epithelial tumours of the ovary, when bilateral complex ovarian masses are demonstrated. Krukenberg tumours represent ovarian metastases that contain mucin-secreting ‘signet-ring’ cells from colonic or gastric neoplasms. Other primary neoplasms that less commonly metastasize to the ovary are breast, lung, and the contra-lateral ovary (not strictly Krukenberg tumours due to the cell types). Imaging findings in metastatic lesions are nonspecific, consisting of predominately solid components or a mixture of cystic and solid areas. In Krukenberg tumours, there are distinctive findings, including solid components secondary to stromal reaction that are low T2WI and high T1W signal

Question 58

A 38-year-old female undergoes investigation for weight loss and abdominal fullness. CT shows large bilateral adnexal masses, ascites and several small omental soft-tissue nodules. MRI demonstrates bilateral sharply marginated ovarian tumours with preservation of the ovarian contours. The tumours consist mainly of hypointense solid material interspersed with foci of high-signal cysts. On post-contrast T1-weighted imaging, the solid components are hyperintense. What is the most likely diagnosis? [B2 Q37]

a. Cystadenocarcinoma
b. Dysgerminoma
c. Krukenberg’s tumour
d. Burkitt’s lymphoma
e. Granulosa cell tumour

Answer 58

Krukenberg’s tumour

Krukenburg’s tumours are metastatic tumours of the ovary. The colon and stomach are the most common primary tumour sites, but other sites, such as the breast, lung, and pancreas, have also been reported. They display characteristic imaging features, including bilateral, sharply marginated oval tumours which preserve the contour of the ovary. Identification of hypointense solid components on T2 corresponding to areas of dense collagenous stroma is also considered characteristic.

Question 59

A 14-year-old girl presents with acute onset of right lower abdominal pain. She reports that she has had similar symptoms previously. Ultrasound shows an ovoid-shaped enlarged right-sided ovary containing multiple enlarged follicles. The ovarian stroma is echogenic compared to adjacent myometrium. There is peripheral blood flow on power Doppler and free fluid within the pelvis. What is the most likely diagnosis? [B2 Q26]

a. Ovarian hyperstimulation
b. Ovarian torsion
c. Polycystic ovary syndrome
d. Theca lutein cysts
e. Serous cystadenoma

Answer 59

Ovarian torsion

Ovarian torsion usually presents in the first three decades of life and is predisposed in patients with co-existing ovarian pathology such as follicular cyst. There may be a history of similar episodes indicating intermittent torsion and spontaneous detorsion. Torsion causes venous outflow obstruction and engorgement of the ovary. Eventually arterial supply is compromised, and necrosis ensues. Diagnosis is suggested by unilateral enlargement of a round or oval-shaped ovary containing multiple enlarged peripheral cysts (caused by transudation of fluid into follicles). Free fluid is present in most cases. Peripheral blood flow may be present but may be absent with infarction.

Ovarian hyperstimulation can present with abdominal pain and may show an enlarged multicystic ovary associated with ascites. However, the condition usually arises from ovarian hormone stimulation in the setting of infertility. Polycystic ovary syndrome typically presents with menstrual disturbance, obesity, and hyperandrogenism.

Question 60

On the third day postpartum, a 25-year-old female develops right-sided lower abdominal pain and breathlessness. CT pulmonary angiogram confirms a pulmonary embolus. Bilateral leg Doppler scan is normal. Which of the following diagnoses requires the most serious consideration? [B4 Q100]

a. Appendicitis
b. Right ovarian vein thrombosis
c. Torsion of ovarian cyst
d. Broad ligament haematoma
e. Pelvic abscess

Answer 60

Right ovarian vein thrombosis

The puerperium is a hypercoagulable state, and puerperal endometritis can seed bacteria along the ovarian vein. Eighty percent of thromboses are on the right and 14% are bilateral. Incidence is between 1 in 600 and 1 in 2000 deliveries. On contrast-enhanced CT, a tubular structure with low-density centre and peripheral enhancement is seen. Complications include inferior vena caval thrombosis, pulmonary embolus (25%), septicaemia, metastatic abscess formation, and death (5%).

Question 61

A 23-year-old woman is referred for an MRI of pelvis because of dyspareunia and pelvic pain. The ovaries are normal, but a 6-mm rounded area of high signal on T1WI and T2WI sequences is demonstrated in the left posterolateral aspect of the distal vagina. What is the most likely diagnosis? [B1 Q25]

A. Squamous cell carcinoma of the vagina.
B. Urethral diverticulum.
C. Nabothian cyst.
D. Bartholin’s gland cyst.
E. Vaginal septum.

Answer 61

Bartholin’s gland cyst.

Bartholin’s glands are located behind the labia minora and their ducts open onto the posterolateral vestibules on each side. The cysts are due to blockage of the ducts and retention of secretions. They are common in reproductive age and are usually cystic in appearance (high T2WI signal). Their T1WI signal is variable and can be high due to mucoid content. They are usually discovered as incidental findings on imaging for another cause, although they may be palpable or clinically visible. The radiologist should recognize them as a benign pathology.

Primary carcinoma of the vagina is rare, as 80–90% of tumours affecting the vagina are due to extension of primary bladder, cervical, vulval, or rectal tumours. Ninety per cent of primary carcinomas are squamous cell carcinoma. The majority occur in elderly women and the two most common presenting complaints are vaginal discharge and bleeding. Squamous cell carcinomas of the vagina are usually of low T1WI and intermediate T2WI signal. As for vulval and cervical squamous cell carcinoma, human papilloma virus (HPV) infection is a risk factor.

Urethral diverticula are best seen on T2WI sequences as hyperintense lesions adjacent to or surrounding the urethra: a connection to the urethra is not always seen. They are usually of low signal on T1WI sequences. They predispose to stones (low signal on T2WI sequences) and carcinoma (enhancing on T1W fat saturation post gadolinium).

Nabothian cysts are found at the external os of the cervix. They are benign retention cysts that develop secondary to obstruction of endocervical glands. They have high T2WI signal and may have high T1WI signal due to mucinous content. They are usually multiple and measure less than 2 cm. They become clinically relevant when they are mistakenly diagnosed as adenoma malignum, a subtype of mucinous adenocarcinoma of the cervix.

A vaginal septum is a low-signal T2WI band. If transverse, it may present in adolescence with primary amenorrhea and abdominal pain, and an abdominal mass if complete. A longitudinal septum is usually asymptomatic and is associated with duplication of the uterus, cervix, or vagina.

Question 62

A 23-year-old woman undergoes investigation for dyspareunia. Pelvic ultrasound was unremarkable. MRI demonstrates a 1cm thin-walled ovoid cystic lesion at the anterolateral aspect of the upper vagina. It is homogeneously hypointense on T1 and shows marked hyperintensity on T2. What is the most likely diagnosis? [B2 Q14]

a. Bartholin cyst
b. Nabothian cyst
c. Cervical fibroid
d. Gartner duct cyst
e. Cervical polyp

Answer 62

Gartner duct cyst

Gartner’s duct cysts are remnants of mesonephric ducts and have a reported incidence of 1–2%. They are ovoid, thin-walled cysts located at the anterolateral aspect of the upper vagina and generally measure less than 2 cm. They may contain proteinaceous material, making them slightly hyperintense on T1. They may be associated with Herlyn–Werner–Wunderlich syndrome (ipsilateral renal agenesis and ipsilateral blind vagina) and ectopic ureter inserting into the cyst.

Bartholin cysts are located at the lateral introitus adjacent to the labia minora. Nabothian cysts are epithelial inclusion cysts which develop in the endocervical canal and are most commonly found in the perimenopausal period. Cervical fibroids and cervical polyps show mainly as solid lesions.

Question 63

A patient has a squamous cell carcinoma of the vulva. An MRI is performed for locoregional staging. There are significantly enlarged inguinal lymph nodes ipsilateral to the primary tumour, but none contralaterally. A short axis, ipsilateral, 1.2 cm external iliac node is also identified that has signal characteristics identical to the primary tumour throughout. Which of the following is the most accurate nodal staging? [B4 Q33]

a. Nx
b. N0
c. N1
d. N2
e. N3

Answer 63

N1

NX is used when regional nodes cannot be assessed, and N0 when there are no involved regional nodes. N1 denotes ipsilateral involved femoral or inguinal lymph nodes. N2 signifies bilateral regional nodal involvement. All intrapelvic nodes are regarded as metastases and therefore do not influence the N stage. There is no N3 for vulval cancer.

Question 64

Lymphatic drainage from the lower third of the vagina is normally first to which of the following lymph node groups? [B4 Q55]

a. obturator
b. internal iliac
c. external iliac
d. inguinal
e. retroperitoneal

Answer 64

Inguinal

The upper two-thirds of the vagina drain to the pelvic nodes, which is of relevance when imaging vaginal cancer. This cancer is uncommon, representing 1–2% of gynaecological malignancy. Eighty-five percent of cases of vaginal cancer are squamous and 15% are adenocarcinoma. Clear-cell carcinoma is a rare form of adenocarcinoma found in young patients with in utero diethylstilbestrol exposure. Even less common are melanoma, sarcoma and adenosquamous carcinoma occurring as vaginal primaries. The two commonest cell types have different natural histories. Adenocarcinoma tends to involve pelvic and is more likely to involve supraclavicular lymph nodes, while squamous carcinomas are more likely to give rise to liver metastases. They are equally likely to metastasize to the lungs.

Question 65

MRI is performed for locoregional staging of vaginal cancer. Which of the following descriptions is the most likely appearance on a T2W sequence, given a small primary tumour confined to the vagina? [B4 Q60]

a. central high signal within the vagina; focal homogeneous, low-signal mass not breaching the surrounding ring of intermediate-signal vaginal wall
b. central high signal within the vagina; focal homogeneous, high-signal mass not breaching the surrounding low-signal vaginal wall
c. central high signal within the vagina; focal homogeneous, intermediate-signal mass breaching the surrounding low-signal vaginal wall
d. central high signal within the vagina; focal homogeneous, intermediate-signal mass not breaching the surrounding low-signal vaginal wall
e. central intermediate signal: focal homogeneous, high-signal mass contained by low-signal vaginal wall

Answer 65

Central high signal within the vagina; focal homogeneous, intermediate-signal mass not breaching the surrounding low-signal vaginal wall

Vaginal cancer

The vaginal epithelial layer and mucus are bright on T2W images. This is normally surrounded by low-signal (fibromuscular) vaginal wall.
Tumours are typically intermediate signal on T2W images.
If gadolinium is used, cancers often have early phase enhancement.
Large tumours may have central necrosis.

T1 tumours do not breach the low-T2-signal vaginal wall, whereas T2 tumours do and extend into the paracolpal fat. T3 tumours reach the pelvic side wall while T4 tumours extend beyond the true pelvis or involve bladder or rectal mucosa.

Question 66

A 23-year-old female presents with acute lower abdominal pain. She has been sexually active since the age of 15 years. Ultrasound shows a well-defined, oval-shaped, relatively thin-walled, anechoic fluid-filled structure lying adjacent to the left lateral wall of the uterus. The mass appears septated although the septae do not fully cross the lumen. What is the most likely diagnosis? [B1 Q39]

a. Hydrosalpinx
b. Tubo-ovarian abscess
c. Haemorrhagic ovarian cyst
d. Endometrioma
e. Thrombosed ovarian vein

Answer 66

Hydrosalpinx

Hydrosalpinx describes a fallopian tube filled with fluid. The fluid is most often anechoic. When the fluid becomes infected, the term pyosalpinx is used and the fluid contents tend to be echogenic. Hydro/pyosalpinx appear as tortuous, well-defined, fluid-filled, oval-shaped structures which extend from the cornua to the ovaries. They are often mistaken for multicystic adnexal masses or septated ovarian cysts due to apparent internal septations. However, the septa, actually the folded wall of the fallopian tube, do not cross the lumen completely. Hydro/pyosalpinx occur most commonly as a result of acute salpingitis and pelvic inflammatory disease (history of early sexual activity/multiple sexual partners). They have also been reported following pelvic surgery.

Tubo-ovarian abscesses tend to be multilocular, irregular, thick-walled, complex masses containing debris and internal septations. Internal fluid-fluid levels or gas may also be seen.

Question 67

HSG shows small diverticular outpouchings in the isthmic portion of the right fallopian tube with distal tube occlusion. What is the diagnosis? [B3 Q41]

a. Salpingitis isthmica nodosa (SIN)
b. Tubal polyps
c. Adenomyosis
d. Asherman’s syndrome
e. Ectopic pregnancy

Answer 67

Salpingitis isthmica nodosa (SIN)

SIN is associated with pelvic inflammatory disease and a higher risk of ectopic pregnancy.

Question 68

A 25-year-old female undergoes ultrasound scan of the pelvis for low abdominal pain. A gas reflection is seen within the uterine cavity. Which of the following is the likely cause of the pain? [B4 Q59]

a. endometriosis
b. adenomyosis
c. endometritis
d. endometrial carcinoma
e. tubo-ovarian abscess

Answer 68

Endometritis

Endometritis is the commonest cause of gas in the uterus. Gas is also seen in the uterus when a submucosal fibroid becomes infected, when necrotic neoplastic tissue is metabolized by bacteria, because of fistula to the gastrointestinal tract, in pyometra secondary to cervix obstruction by cancer, or in cases of gas gangrene due to clostridial infection following septic abortion. Ovarian gas can be seen with infection within an ovarian neoplasm. Numerous gas-filled spaces in the vaginal submucosa and exocervix can occur in pregnancy; this is termed ‘vaginitis emphysematosa’.

Question 69

A 28-year-old female has a hysterosalpingogram for infertility. Both fallopian tubes distend progressively with contrast injection but without peritoneal spill of contrast. A delayed plain abdominal radiograph shows continued distension of both tubes by dense collections of contrast and no peritoneal spill. Given these findings, which of the following is the most likely predisposition to infertility for this patient? [B4 Q78]

a. tuberculosis
b. endometriosis
c. pelvic inflammatory disease
d. submucosal uterine fibroids
e. Asherman’s syndrome

Answer 69

Pelvic inflammatory disease

The patient’s fallopian tubes are occluded, giving bilateral hydrosalpinx. The commonest cause of proximal or distal tubal occlusion is pelvic inflammatory disease. Endometriosis, infection following birth or abortion, and tuberculosis are other causes.

Indications for hysterosalpingogram include: infertility, recurrent miscarriage, assessment of the tubes after surgery and assessment of the integrity of a post-caesarean uterine scar.

Contraindications are pregnancy, purulent vulval or cervical discharge, pelvic inflammatory disease in the preceding 6 months and contrast sensitivity. Historical contraindications include the immediate post-menstruation phase and recent dilatation and curettage, because of the risks associated with intravasation of oily contrast media.

Question 70

A 35-year-old Asian woman presents with lower abdominal pain and fever. Transvaginal ultrasound shows bilateral, homogenous, extraovarian, tubular lesions containing fluid with featureless walls. What is the most likely diagnosis? [B5 Q8]

a. Cystic ovarian tumour
b. Chocolate cysts
c. Bilateral hydrosalpinx
d. Paraovarian cysts
e. Small bowel

Answer 70

Bilateral hydrosalpinx

This is usually a result of continuous secretion of the tubal epithelium into the lumen of a fallopian tube obstructed at two sides. Ultrasound shows undulating or folded tubular structures which are extraovarian. This may be secondary to endometriosis, adhesions, infection, tubal surgery or ectopic pregnancies.

Question 71

You are asked to perform an antenatal ultrasound examination and note that the placenta has an unusual morphology. You see an additional lobule, which is separate from the main bulk of the placenta. What is this variant of placental morphology known as? [B1 Q28]

a. Circumvallate placenta
b. Bilobed placenta
c. Placenta membranacea
d. Succenturiate placenta
e. Placenta accreta

Answer 71

Succenturiate placenta

Succenturiate placenta is an additional lobule separate from the main bulk of the placenta. The significance of this variant is the rupture of vessels connecting the two components or retention of the accessory lobe with resultant post-partum haemorrhage.

Question 72

You are asked to assess a 24-year-old woman with TVUS. The patient presents with lower abdominal cramps and is approximately 5 weeks post last menstrual period (LMP). Her pulse and blood pressure are normal. β-HCG levels suggest that the patient is pregnant. On TVUS, no adnexal mass or free fluid is seen. Which of the following findings would you expect to see in the uterus to confirm that the patient does not have an ectopic pregnancy? [B1 Q44]

a. Pseudogestational sac
b. Normal endometrium
c. Trilaminar endometrium
d. Double decidual sac sign
e. Thin-walled decidual cyst

Answer 72

Double decidual sac sign

Question 73

You are asked to assess a 24-year-old woman with TVUS. The patient presents with lower abdominal cramps and is approximately 5 weeks post last menstrual period (LMP). Her pulse and blood pressure are normal. β-HCG levels suggest that the patient is pregnant. On TVUS, no adnexal mass or free fluid is seen. Which of the following findings would you expect to see in the uterus to confirm that the patient does not have an ectopic pregnancy?
A. Pseudogestational sac.
B. Normal endometrium.
C. Trilaminar endometrium.
D. Double decidual sac sign.
E. Thin-walled decidual cyst

Answer 73

Double decidual sac sign.
All the other answers are findings in the uterus that may be associated with ectopic pregnancy. In normal pregnancies, TVUS can demonstrate an intradecidual sign approximately 4.5 weeks after the last menstrual period. The intradecidual sign is a small collection of fluid that is eccentrically located within the endometrium and is surrounded by a hyperechoic ring. At approximately 5 weeks, the double decidual sac sign can be visualized. This consists of two concentric hyperechoic rings that surround an anechoic gestational sac in a normal intrauterine pregnancy. The secondary yolk sac may be identified at TVUS at approximately 5.5 weeks. Embryonic cardiac activity should also be visualized at TVUS at approximately 5–6 weeks, when the gestational sac measures at least 18 mm or when the embryonic pole measures at least 5 mm. A pseudogestational sac is a thick decidual reaction surrounding intrauterine fluid and is seen in approximately 10% of ectopic pregnancies. A trilaminar endometrium is formed during the late proliferative phase of the menstrual cycle. When an abnormal pregnancy is suspected based on laboratory results, the absence of a true gestational sac in the presence of a trilaminar endometrium is highly suggestive of ectopic pregnancy. Thin-walled decidual cysts are seen at the junction of endometrium and myometrium and may be seen in both normal and abnormal pregnancies. The thin wall differentiates it from a true gestational sac.

Question 74

A 24-year-old woman attends A&E with lower abdominal pain and vaginal bleeding. A pregnancy test is positive. She is haemodynamically stable, and an ultrasound is requested to confirm the presumed diagnosis of an ectopic pregnancy. Which of the following is the most common location for an ectopic pregnancy?
a. Cervix
b. Ovary
c. Abdominal cavity
d. Ampullary portion of the fallopian tube
e. Interstitial portion of the fallopian tube

Answer 74

Ampullary portion of the fallopian tube
The most common site of implantation is the fallopian tube, which accounts for over 90% of ectopic pregnancies. Ovarian and abdominal sites account for only approximately 3% and 1%, respectively. Within the fallopian tube the most common site is the ampulla (73%) followed by the fimbrial and interstitial regions.

Question 75

A 26-year-old pregnant woman attends for an obstetric ultrasound at 37 weeks. She is shown to have polyhydramnios. Which of the following would be a possible cause?
a. Cystic adenoid malformation
b. Ventricular septal defect
c. Infantile polycystic kidney disease
d. Posterior urethral valves
e. Intrauterine growth retardation

Answer 75

Cystic adenoid malformation
The remainder of the conditions listed above will cause oligohydramnios. Polyhydramnios is defined as amniotic fluid volume >1500–2000 cm³ at term. Most cases are due to maternal factors, with diabetes causing the majority of these. Oligohydramnios is defined as an amniotic fluid volume of <500 cm³ at term; the most common causes include demise of the fetus, drugs, and renal anomalies.

Question 76

A 29-year-old woman with a history of three previous failed pregnancies attends the ultrasound department for a scan. She has had a positive pregnancy test. Which of the following is not necessarily indicative of a failed pregnancy?
a. A crown rump length of 11mm with no heartbeat detectable on TA scan
b. A crown rump length of 5mm with no heartbeat detectable on TV scan
c. A gestation sac, mean sac diameter >20mm with no visible yolk sac
d. A gestation sac, mean sac diameter >25mm with no visible embryo
e. A flat M mode scan

Answer 76

A crown rump length of 5 mm with no heartbeat detectable on TV scan
In order to assess the presence or absence of a heartbeat accurately on TV scanning, the crown rump length needs to be >6 mm. On TA scanning the crown rump length needs to be >10 mm to accurately assess the absence of a heartbeat. The other options all represent signs of fetal demise. Usually, two qualified ultrasound practitioners are required to assess a fetus if there is concern regarding embryonic demise.

Question 77

An 18-year-old woman who is 32 weeks pregnant is referred for an obstetric ultrasound for ongoing abdominal pain. She is shown to have a small placenta relative to gestational age. Which one of the following would be a possible cause?
a. Molar pregnancy
b. Maternal diabetes
c. Umbilical vein obstruction
d. Pre-eclampsia
e. Maternal anaemia

Answer 77

Pre-eclampsia

Small placenta:
Pre-eclampsia
IUGR
chromosomal abnormality
intrauterine infection.

Large placenta: (>5 cm)
Maternal diabetes
Chronic intrauterine infection (e.g. syphilis)
Maternal anaemia
Thalassaemia
Twin–twin transfusion syndrome.

Fetal chromosomal abnormalities may cause either a large or small placenta.*

Question 78

A 27-year-old woman who is 32 weeks pregnant is admitted with acute abdominal pain. The surgical team have requested an abdominal MRI to further investigate her pain before considering laparotomy. You are asked to protocol the request card. Which one of the following statements is correct?
a. The mother should be asked to lie prone for the scan
b. MRI should be avoided in the third trimester of pregnancy
c. Gadolinium diethylenetriaminepentaacetic acid (DTPA) chelate does not cross the placenta
d. Gadolinium-based contrast material crosses the placental membrane and circulates through the amniotic fluid
e. MRI would be the first imaging modality of choice

Answer 78

Gadolinium-based contrast material crosses the placental membrane and circulates through the amniotic fluid
The use of MRI in the evaluation of abdominal pain in pregnant patients is increasing. The primary imaging modality of choice, however, remains ultrasound, and MRI is usually reserved for situations where the ultrasound findings are equivocal. The use of gadolinium is not usually necessary in the investigation of abdominal pain in the acute setting and there is little evidence as to its effect on the fetus.

Question 79

Regarding molar pregnancy ultrasound:
a. High velocity, low impedance waveforms on Doppler occur later in a molar pregnancy than in a normal pregnancy
b. The uterine artery Pulsatility Index (PI) is proportional to arterio-venous shunting
c. Patients with a low PI are more likely to become resistant to single drug therapy with methotrexate
d. Low impedance waveforms with high diastolic velocities are findings in a normal pregnancy
e. A minimum normal UAPI is > 2.5

Answer 79

Patients with a low PI are more likely to become resistant to single drug therapy with methotrexate
Minimal normal UAPI > 1.5. High velocity low impedance waveforms on Doppler are findings in a normal pregnancy but are found in the first and second trimesters in molar pregnancy (far earlier than in a normal pregnancy). Low PI indicates increased AV shunting and are more likely to become resistant to single drug therapy with methotrexate.

Question 80

At the 20-week fetal anomaly ultrasound scan, the cervix of a 25-year-old primagravida is measured to be 22 mm long. She is most likely to have been treated with which of the following?
a. Oestrogens
b. Progestogens
c. Heparin
d. Salbutamol
e. Corticosteroids

Answer 80

Oestrogens
Uterine cervix length can be measured transabdominally or trans-vaginally. With the former approach, the measurement can be 10% greater than the corresponding transvaginal measurement, because, while the full urinary bladder is a desirable acoustic window, it increases the cervical length. Transvaginally, the normal cervical length is 40±8 mm in the first 14 weeks of gestation, decreasing thereafter by 2 mm per week. A short cervix (measuring ≤ 25 mm at 20 weeks) is associated with an increased risk of premature delivery. Progesterone can be administered to reduce the risk of preterm birth. Oestrogens can be used to maintain pregnancy.

Question 81

Which of the following would you expect to see on ultrasound in a hydatidiform molar pregnancy?
a. Snowstorm appearance
b. Double decidual sac sign
c. Low-resistance Doppler flow patterns
d. Hypervascularization of the placenta
e. Calcified umbilical vessels

Answer 81

Snowstorm appearance
The snowstorm appearance is characteristic of molar pregnancies on ultrasound. Molar pregnancies are abnormal growths within the uterus that arise from placental tissue. They are either complete or partial molar pregnancies. A complete molar pregnancy has no fetus or amniotic fluid. Instead, the uterus is filled with hydropic villi, which create the characteristic ultrasound snowstorm pattern. Partial moles, on the other hand, may have some fetal parts and amniotic fluid, but there are still abnormal placental structures. This appearance is the result of the multiple cystic spaces within the placental tissue.

Question 82

A 30-year-old woman attends for a first-trimester ultrasound scan. Her last menstrual period was approximately 10 weeks prior to the scan, but she is unsure of the exact dates. What is the most accurate ultrasound measurement for dating the pregnancy at this stage? [B4 Q11]

a. biparietal diameter
b. mean gestational sac diameter
c. crown–rump length
d. femur length
e. abdominal circumference

Answer 82

Crown-rump length

Estimation of gestational age is most accurate in the first trimester. The crown–rump length is used, which has a range of +0.7 weeks. Beyond about 13 weeks, the measurement becomes less reliable as the fetus becomes increasingly flexed. In the very early first trimester, the mean gestational sac diameter can be used to estimate gestation age with similar accuracy, but this measurement should not be used once the embryo can be seen. Biparietal diameter (or alternatively head circumference) becomes the most reliable measurement in the second trimester with an accuracy of +1.2 weeks up to 20 weeks. Femur length is less precise. Abdominal circumference is the least accurate measurement and is generally used only to assess fetal growth and proportionality. Estimation of gestational age becomes considerably less reliable with advancing pregnancy; beyond about 22 weeks, fetal growth becomes the main determinant of fetal size.

Question 83

Endoanal ultrasound scan is performed on a 20-week pregnant patient who sustained perineal damage during a previous vaginal delivery, to guide the method of delivery. Scarring is seen involving more than 50% of the external sphincter, but the internal anal sphincter is intact. Which of the following best represents the degree of perineal injury? [B4 Q29]

a. first
b. second
c. third (3a)
d. third (3b)
e. third (3c)

Answer 83

Third (3b)

First-degree perineal tear: involves skin only.
Second-degree tear: Perineal muscle is torn - includes episiotomy.
Third-degree injury : Involves anal sphincter - subdivided into 3 types:
* 3a < 50% of external sphincter.
* 3b > 50% of external sphincter.
* 3c Internal sphincter torn.
Fourth-degree tear: Extending into the anal epithelium

Question 84

A 23-year-old woman is found on a 10-week dating ultrasound scan to have a twin pregnancy. A repeat examination prompted by blood spotting per vaginum, later attributed to a cervical erosion, shows a singleton pregnancy and no evidence of the twin. What should this be termed? [B4 Q42]

a. foetus papyraceus
b. vanishing twin
c. fetal death in utero
d. immune fetal hydrops
e. non-immune fetal hydrops

Answer 84

Vanishing twin

‘Vanishing twin’ occurs at less than 13 weeks when one twin is completely resorbed with no residuum evident on ultrasound scan. In foetus papyraceus, one twin is compressed and seen plastered to the adjacent membranes. Fetal death in utero or intrauterine death is signalled by absent heart and somatic movement in the second and third trimesters. Hydrops is excess total body water manifested as extracellular liquid accumulation in tissues and serous cavities. In hydrops of immune origin, antibodies to red blood cells are present.

Question 85

On the 20-week foetal anomaly scan, it is noticed that there is less than 1 mm of hypoechoic myometrium between placenta and echo-bright uterine serosa. An MRI is performed. On T2W images, the placenta is heterogeneous and bright, and causes junctional zone interruption and marked focal myometrial thinning. The serosa looks intact. These findings describe which of the following?

a. placenta accrete
b. placenta increta
c. placenta percreta
d. placenta praevia
e. placental abruption

Answer 85

Placenta increta

The normal decidua forms a barrier between chorionic villi and uterus, preventing deep invasion of placental material. An underdeveloped or absent decidua permits direct contact of chorionic villi with the myometrium, known as placenta accreta. When the villi invade the myometrium, it becomes placenta increta; if the serosa is penetrated, it is placenta percreta. Diagnosis is difficult on ultrasound scan, but MRI can help. Risk factors are previous caesarean section and myomectomy, multiparity and increasing maternal age. Complications include maternal haemorrhage, premature delivery, intrauterine growth retardation and 5% chance of perinatal death. To protect the mother, balloon catheters can be placed over the internal iliac arteries prior to caesarean delivery.

Question 86

During a 20-week fetal anomaly scan, it is noticed that the umbilical cord has only two vessels. Which of the following conditions is most frequently associated with this finding? [B4 Q55]

a. triploidy
b. Turner’s syndrome
c. trisomy 18
d. trisomy 13
e. Down’s syndrome

Answer 86

Trisomy 18

In 67% of cases of single umbilical artery, there are chromosomal abnormalities. Trisomy 18 has a stronger association than trisomy 13, Turner’s syndrome, or triploidy. Down’s syndrome is not associated.

Question 87

During the third trimester of pregnancy, a multiparous, 48-year-old woman who is a smoker experiences bleeding per vaginum. Ultrasound scan shows the edge of the placenta to cover the whole of the internal cervical os. It is decided that delivery will be by caesarean section, for which of the following reasons? [B4 Q56]

a. placental separation
b. low-lying placenta
c. marginal placenta praevia
d. complete placenta praevia
e. placental abruption

Answer 87

Complete placenta praevia

This occurs in 1 in 200 pregnancies, and the incidence rises with increasing maternal age, multiparity, smoking, and previous caesarean section. Delivery is by caesarean section. Third-trimester bleeding occurs in 90% of cases of placenta praevia, with premature delivery and perinatal and maternal death as other complications. A low-lying placenta is one within 2 cm of the internal cervical os. Marginal placenta praevia describes a placental edge up to the os. Partial praevia covers some of the os. From 60% to 90% of patients with placenta praevia in the second trimester have a normal placenta by term because of differential growth of the lower uterine segment.

Question 88

A 28-week pregnant patient known to have uterine fibroids reports abdominal pain for the preceding 4 weeks. On questioning, she admits to small amounts of brown/red vaginal loss. Ultrasound scan shows a complex but predominantly hypoechoic collection between the uterine wall and placenta. Which of the following is the most likely explanation for the imaging findings? [B4 Q58]

a. acute placental abruption
b. placental abruption 1 week previously
c. placental abruption 4 weeks previously
d. placenta membranacea
e. ectopic pregnancy

Answer 88

Placental abruption 1 week previously

Abruption can be regarded as premature separation of the placenta from the uterine wall secondary to maternal haemorrhage after 20 weeks’ gestation. Manifestations include vaginal bleeding, pain, and disseminated intravascular coagulation. Risk factors include hypertension (pre-eclampsia), previous abruption, smoking, cocaine, leiomyoma, idiopathic factors, fetal malformation, and trauma. Placental abruption is responsible for 15–25% of perinatal deaths. On ultrasound scan, acute haemorrhage appears hyperechoic or isoechoic and may be difficult to distinguish from the adjacent placenta. The haematoma forms a complex hypoechoic collection within 1 week of abruption and usually appears as an anechoic collection within 2 weeks. Placenta membranacea refers to the presence of placental villi in the peripheral membranes.

Question 89

In antenatal ultrasound scanning, which of the following is a major marker associated with trisomy 21? [B4 Q66]

a. echogenic bowel before 20 weeks
b. echogenic intracardiac focus
c. brachycephaly
d. small cerebellum
e. hydrothorax

Answer 89

Hydrothorax

Major markers for Down’s syndrome include ventriculoseptal defect, cystic hygroma, omphalocele, duodenal atresia, hydrothorax, mild cerebral ventricular dilatation, corpus callosum agenesis, and imperforate anus. The other options given are minor markers.

Question 90

In a twin pregnancy, entanglement of the umbilical cords is discovered. Which of the following best describes the genetic and anatomical relationship of the twins? [B4 Q67]

a. dizygotic; both intrauterine
b. monozygotic; dichorionic diamniotic
c. monozygotic; monochorionic diamniotic
d. monozygotic; monochorionic monoamniotic
e. dizygotic; one ectopic

Answer 90

Monozygotic; monochorionic monoamniotic

For cord entanglement, the twins must be in the same amniotic sac. Dizygotic twins are non-identical and result from fertilization of two separate ova.

Question 91

A 25-year-old woman with pelvic inflammatory disease has a raised serum b-hCG level. Ultrasound scan reveals an empty uterine cavity and an extrauterine amniotic sac. MRI some weeks later shows circumferential bowel involvement by the placenta, which appears to be continuous with the bowel wall muscle. Which of the following is the most compelling reason for a further follow-up MRI? [B4 Q80]

a. to check that the placenta has been fully removed by surgery
b. to check for response to chemotherapy
c. to ensure that the placenta involutes following delivery and no abscess has developed
d. to stage the gestational trophoblastic neoplasia
e. to date the pregnancy

Answer 91

To ensure that the placenta involutes following delivery and no abscess has developed

The history and imaging features are of extrauterine abdominal pregnancy, which occurs when the fertilized ovum implants directly on the peritoneal surface of the abdomen. This is more likely when the prevalence of pelvic inflammatory disease and ectopic pregnancy is higher. The diagnosis is often established with ultrasound scan. MRI can be used to identify the location and assess adherence to abdominal viscera by the placenta. MR angiography can suggest feeding arteries. MRI at this stage also has a role in detecting fetal anomalies. If the placenta is adherent to abdominal viscera, it is not removed, because this could precipitate catastrophic arterial haemorrhage. Therefore, MRI is performed later to ensure involution of the placenta and exclude abscess formation. Placental adherence is suggested on MRI when it is contiguous with liver or spleen parenchyma, shows circumferential involvement of bowel, or shows continuity with muscle of bowel wall.

Question 92

A 45-year-old who is assumed to be pregnant presents with a uterus large for dates and hyperemesis gravidarum. The b-hCG levels are raised. Transvaginal ultrasound scan shows hyperechoic soft tissue with cysts filling the uterine cavity and a septated large left ovarian cyst. Which of the following additional features favors the diagnosis of complete hydatidiform mole as opposed to any other gestational trophoblastic disease? [B4 Q93]

a. no fetal parts
b. dysmorphic fetus
c. associated prominent vessels
d. pelvic lymph node involvement
e. lung metastases

Answer 92

No fetal parts

Gestational trophoblastic disease (GTD) is abnormal proliferation of the trophoblast, which can give rise to a complete or partial hydatidiform mole, invasive mole, or choriocarcinoma. Increasing age and previous GTD are risk factors. Elevation of b-hCG aids diagnosis and is of value in assessing risk of metastatic disease (hence prognosis) and can be used to assess treatment response or detect recurrence. Complete moles have a higher malignant potential than partial moles. A complete mole has no fetal parts and has a 46,XX or, less often, a 46,XY karyotype. A partial mole has fetal parts and a triploid karyotype with 69 chromosomes. Eighty per cent of hydatidiform moles resolve with evacuation, 15% are locally invasive, and 5% give rise to metastatic choriocarcinoma. When GTD is staged, there are no ‘regional’ nodes, and any nodal spread is considered metastatic with a significant worsening of prognosis. On ultrasound, the mole is echogenic but with a vesicular appearance. Fifty per cent of cases are associated with a large, septated theca lutein cyst. On Doppler ultrasound scan, they have prominent associated vessels with low resistance and high peak systolic velocity.

Question 93

A 36-year-old woman was diagnosed with complicated pregnancy on transvaginal ultrasound scan. What is the following is unlikely to be a possible diagnosis? [B5 Q33]
(a) Deflated yolk sac
(b) Hypoechoic area behind the choriodecidua
(c) Septated fluid behind the fetal neck
(d) A very large gestational sac relative to the embryo
(e) Herniated midgut into umbilical cord at 9 weeks

Answer 93

Herniated midgut into umbilical cord at 9 weeks
All other findings on ultrasound point to complicated pregnancy. Physiological herniation of bowel is seen from 8–11 weeks

Question 94

A 36-year-old woman with primary infertility was sent for hysterosalpingography. Which of the following is an absolute contraindication to this procedure? [B5 Q36]
(a) Previous caesarean section
(b) Reconstructive tubal surgery in last 6 months
(c) Menstruation
(d) Congenital abnormalities of the genitalia
(e) Treated pelvic infection

Answer 94

Menstruation

Ongoing bleeding at the time of examination is an absolute contraindication to hysterosalpingography. It increases the risk of infection, and risks flushing endometrial tissue into the abdomen.

Recent tubal surgery within last 6 weeks is also a contraindication for this procedure. Other contraindications include pregnancy, immediate pre- and post-menstrual phases, recent untreated pelvic infection, and contrast allergy.

Question 95

A 40-year-old female with uterine fibroids is referred for uterine artery embolization. Which of the following statements regarding the relevant arterial anatomy is incorrect? [B1 Q17]
(a) Uterine artery is the first or second branch of the anterior division of internal iliac artery in 51% of cases.
(b) The ipsilateral ovarian artery often replaces an absent uterine artery.
(c) The ovarian artery has a characteristic corkscrew appearance on angiogram.
(d) Utero-ovarian anastomosis is identified in less than 5% of cases.
(e) Ovarian artery supply to fibroids is more frequently found in women with a history of previous pelvic surgery.

Answer 95

Utero-ovarian anastomosis is identified in less than 5% of cases.
Uterine arteries are the predominant source of blood supply to the fibroids in most cases. There is considerable variation in the pelvic arterial anatomy, a thorough knowledge of which is essential to carry out uterine artery embolization safely and effectively.

Utero-ovarian anastomosis is seen in 10–30% of cases and left-to-right uterine anastomosis in 10% of cases.

Question 96

A 46-year-old female with pressure symptoms related to uterine fibroids is referred for fibroid embolization. Which of the following complications is the patient at increased risk of? [B1 Q47]
(a) Uterine sepsis.
(b) Fibroid passage.
(c) Fibroid regrowth.
(d) Ovarian dysfunction.
(e) Hysterectomy.

Answer 96

Ovarian dysfunction.
Ovarian dysfunction is a known complication of fibroid embolization. The exact mechanism is not known, but inadvertent embolization of the ovaries via a uterine–ovarian anastomosis has been suggested. There is a higher prevalence of uterine–ovarian anastomosis in women over 45 years of age and that puts them at increased risk.

Question 97

A general practitioner performs a vaginal examination prior to intended removal of an intrauterine contraceptive device. The locator device cannot be seen or palpated. What is the most appropriate initial investigation for this patient? [B5 Q8]
(a) abdominal radiograph
(b) pelvic ultrasound scan
(c) pelvic CT
(d) pelvic MRI
(e) hysteroscopy

Answer 97

Pelvic ultrasound scan
The device should be seen within the endometrial cavity on ultrasound scan as an echo-bright structure casting an acoustic shadow. If it is not identified in the uterus on ultrasound scan, then a plain abdominal film is indicated to exclude perforation and migration.