Uterus, Ovaries and Adnexa Flashcards
1
Q
What is the space of Retzius?
Describe the displacement pattern for a mass in the space of Retzius.
A
- The space of Retzius is an extraperitoneal potential space between the pubic symphysis and the bladder.
- A mass in the space of Retzius (such as a hematoma) can displace the bladder posteriorly.
- In contrast, pelvic or abdominal masses will displace the bladder inferiorly or anteriorly.
2
Q
Describe the cervix in US
What is a Nabothian cyst?
A
- The cervix is seen transvaginally in the sagittal plane as the most proximal portion of the uterus directly posterior to the angle of the bladder.
- The cervix is attached to the posterior edge of the bladder by the parametrium.
- The cervix and uterus normally form a 90-degree angle.
- Nabothian cysts are normal retention cysts due to occlusion of cervical glands.
3
Q
Describe the true and false pelvis
A
- The linea terminalis is a bony landmark separating the true (inferior) pelvis from the false / superior pelvis. The linea terminalis is a composite of the arcuate line of the ilium, the iliopectineal line, and the pubic crest.
- Normally, the uterus and ovaries are in the true pelvis.
- The dome of a full bladder extends into the false pelvis, pushing small bowel out of the true pelvis. The bladder acts as a sonographic window into the true pelvis.
4
Q
Describe normal variant uterine positions
A
- About 20 degrees of uterine anteflexion is normal. As the bladder fills, the degree of anteflexion decreases.
- Retroversion of the uterus may cause poor visualization of the fundus transabdominally.
- Retroflexion of the uterus may cause even more severe sound attenuation of the uterine fundus.
5
Q
Describe orientation of uterus via transabdominal US
A
6
Q
Describe the uterine scanning orientation in a endovaginal US
A
- The sagittal scan plane is rotated 90 degrees between transabdominal and endovaginal orientation. The patient typically empties her bladder prior to endovaginal scanning.
7
Q
What else should be evaluated when a congenital uterine abnormality is seen?
A
- Congenital uterine abnormalities may be associated with urinary tract abnormalities such as renal ectopia or agenesis. The kidneys should be evaluated if a uterine malformation is seen.
8
Q
The American Fertility Society (now known as the American Society of Reproductive
medicine) Mullerian duct anomalies - Class I
A
Uterine Agenesis/hypoplasia
9
Q
The American Fertility Society (now known as the American Society of Reproductive
medicine) Mullerian duct anomalies - Class II
A
Unicornuate uterus
A unicornuate uterus represents a uterine malformation where the uterus is formed from one only of the paired Müllerian ducts while the other Müllerian duct does not develop or only in a rudimentary fashion.
10
Q
The American Fertility Society (now known as the American Society of Reproductive
medicine) Mullerian duct anomalies - Class III
A
- A didelphys uterus is two completely separate uteri and cervices, with complete endometrium, myometrium, and serosal surfaces on each side. 75% have a vaginal septum.
11
Q
The American Fertility Society (now known as the American Society of Reproductive
medicine) Mullerian duct anomalies - Class IV
A
- A bicornuate uterus has two uterine fundi, with a shared proximal lower uterine segment.
- A bicornuate uterus may be bicornis bicollis (two cervices) or bicornis unicollis (one cervix).
12
Q
The American Fertility Society (now known as the American Society of Reproductive
medicine) Mullerian duct anomalies - Class V
A
- A septate uterus consists of two uterine cavities, divided by a fibrous or muscular septum.
- Septate uterus is the most likely of all uterine anomalies to be implicated in pregnancy loss since the fibrous septal tissue or myometrium is relatively avascular.
- By far most common uterine abnormality
13
Q
The American Fertility Society (now known as the American Society of Reproductive
medicine) Mullerian duct anomalies - Class VI
A
- An arcuate uterus is a small inpouching or concave surface of the fundus, which is considered a normal variant rather than an anomaly.
14
Q
The American Fertility Society (now known as the American Society of Reproductive
medicine) Mullerian duct anomalies - Class VII
A
- In utero exposure to diethylstilbestrol (DES) causes the fetus to develop a hypoplastic uterus with a T-shaped endometrial contour and is associated with an increased risk of clear cell vaginal cancer. DES hasn’t been used since the 1970s.
15
Q
Describe the menstrual cycle, including ovarian, endometrial and hormone fluctuations.
A
16
Q
Measuring the Endometrium
How and when should it be measured?
A
- The thickest portion of the endometrium should be measured transvaginally in the sagittal orientation.
- Ideally, the endometrium should be measured in the menstrual phase.
- Endometrial fluid is not included in the measurement: If endometrial fluid is present, the flanking endometrium is measured and the two components are summed.
17
Q
Cyclical Endometrial Thickness
- Days 1 - 4: Menstrual phase
- Days 5 - 9: Early proliferative
- Days 10 - 14: Late proliferative (preovulatory)
- Days 15 - 28: Secretory
A
- Endometrial thickness <4 mm. The endometrium is a thin, echogenic stripe in the menstrual phase.
- Endometrial thickness 4 - 8 mm.
- Endometrial thickness 6 - 10 mm. Estrogen effects dominate in the proliferative phase, causing increased functional zone thickness. The endometrium becomes trilaminar with a hypoechoic zone between the endometrial cavity and the peripheral echogenic endometrium.
- Endometrial thickness 7 - 14 mm. Progesterone effects dominate in the secretory phase, causing the functional layer to becomes even thicker, soft, and edematous as the spiral arteries become tortuous. The functional layer increases in echogenicity and becomes isoechoic relative to the basal layer. The endometrium reaches its maximum thickness and echogenicity in the late secretory phase.
18
Q
What is an endometrial polyp and what is the US appearance?
How is it more definitively diagnosed?
A
- An endometrial polyp can cause mucous discharge or irregular vaginal bleeding between cycles. Most endometrial polyps are benign, but larger polyps (>1.5 cm) or polyps occurring in postmenopausal patients may have malignant potential.
- Ultrasound shows a focal nodular area of endometrial thickening, often with a feeding vessel by doppler. A polyp is more definitively diagnosed by sonohysterogram, where saline is instilled into the uterus prior to transvaginal ultrasound.
19
Q
Describe Tamoxifen’s effect on the endometrium and US appearance
A
- Tamoxifen is an estrogen agonist/antagonist used in the treatment of breast cancer. It acts as an antagonist at the breast and an agonist at the endometrium.
- Tamoxifen can cause endometrial hyperplasia, metaplasia, and carcinoma.
- Ultrasound shows irregular, cystic endometrium, which may simulate endometrial cancer or endometrial cystic atrophy.
- Most women on tamoxifen are screened by ultrasound every 6 months for endometrial carcinoma.
20
Q
How does endometrial carcinoma present?
Risk factors?
US appearance?
A
- over 95% of endometrial carcinoma presents with postmenopausal bleeding. The main risk factor for endometrial cancer is prolonged estrogen exposure, which occurs with nulliparity, obesity, late menopause, and tamoxifen.
21
Q
Under what length should the postmenopausal endometrium normally in a patient that is not bleeding.
A
- If the patient is not bleeding, the postmenopausal endometrium should be <8 mm thick. Although an incidentally thickened endometrium may be a normal hyperplastic response to estrogen exposure, a thickened endometrium should always be regarded with suspicion for malignancy in a postmenopausal woman.
- If the endometrium is thicker than 8 mm in a postmenopausal woman, the patient should be evaluated further, typically via endometrial biopsy with or without hysteroscopy.
22
Q
What US finding is most suggestive of endometrial carcinoma?
A
- Although uncommonly seen in the absence of bleeding, the finding most suggestive of endometrial carcinoma is the presence of ill-defined margins separating the endometrium and the myometrium.
23
Q
If a patient is bleeding what length would suggest endometrial atrophy?
A
- If the patient is bleeding and the endometrium is less than 5 mm, the bleeding is caused by endometrial atrophy.
- There is negligible risk of endometrial cancer if the thickness is less than 5 mm.
24
Q
Postmenopausal bleeding with endometrium thicker than what length may represent endometrial cancer?
What is the average endometrial thickness with endometrial carcinoma?
A
- Postmenopausal bleeding with an endometrium thicker than 5 mm may represent endometrial carcinoma and further workup is needed. Note that the average endometrial thickness with endometrial carcinoma is 21 mm.
25
What is endometriosis?
What is an endometrioma and what is its classic US appearance?
* Endometriosis is ectopic endometrial tissue outside of the endometrial cavity.
* An endometrioma is a hemorrhagic focus of ectopic endometrial tissue.
* The classic ultrasound appearance of an endometrioma is a **well-defined complex cyst with homogeneous low-level internal echoes and increased through** **transmission****. Small linear echogenic foci are often seen at the cyst periphery.** This classic appearance isn’t always seen and occasionally an endometrioma may appear similar to a neoplasm.
* While the ovary is the most common site of involvement, endometriosis may affect the adnexa, pelvic viscera, or even organs outside of the pelvis, such as the brain.
26
What is adenomyosis, how does it present, and what is its US appearance?
* Adenomyosis is endometrial tissue within the myometrium. Adenomyosis typically presents with menorrhagia and pain.
* Ultrasound shows **heterogeneous myometrium, typically more prominent in the posterior wall, associated with** **subendometrial** **cysts**. The **uterus may be globular and enlarged and there is often poor differentiation of the endometrial-myometrial border.** Focal adenomyosis, known as an adenoma, may simulate a fibroid.
27
What are fibroids?
Epidemiology?
US appearance?
What is a lipoleiomyoma?
* Fibroids are extremely common benign tumors of smooth muscle seen in 25% of white women and 50% of black women over age 30.
* The typical ultrasound appearance of a fibroid is a **slightly heterogeneous, hypoechoic uterine mass with linear bands of** **shadowing**. Calcification is often seen. May **undergo cystic degeneration and appear as an anechoic mass with posterior through** **transmission**.
* A lipoleiomyoma is a variant of fibroid that contains fat and is echogenic.
28
Describe all the fibroid locations
* Intramural: Location in the myometrium is the most common fibroid location.
* Submucosal: A submucosal fibroid may bulge into the endometrial canal, producing pain and bleeding.
* A submucosal fibroid can be resected hysteroscopically if \>50% of the fibroid is intraluminal.
* An intracavitary fibroid is a variant of a submucosal fibroid located nearly entirely within the uterine cavity.
* Subserosal: A subserosal fibroid may simulate an adnexal mass if pedunculated, but doppler will show blood supply coming from the uterus.
* Cervical: Rare, may simulate cervical cancer.
29
What is leiomyosarcoma?
What is one risk factor?
* Malignant transformation of a fibroid to leiomyosarcoma is extremely rare.
* A “funny looking fibroid” is much more likely to be a benign, inhomogeneous fibroid rather than a leiomyosarcoma.
* Tamoxifen increases the risk of leiomyosarcoma in addition to endometrial carcinoma.
30
Talk about endometrial fluid
* It is never normal to have more than a tiny amount of fluid in the endometrial canal.
* In a premenopausal woman, endometrial fluid can be due to bleeding from menses or spontaneous abortion.
* In a postmenopausal woman, endometrial fluid can be due to cervical stenosis, and a careful **evaluation** **for** **cervical malignancy should be performed**.
31
Describe two kinds of uterine infections
* **Endometritis** is inflammation or infection of the endometrium and is commonly seen postpartum, typically with no specific findings on ultrasound. Gas in the uterus may be normal up to 3 weeks postpartum (seen in 7% of normal cases), but gas in the uterus later than 3 weeks after delivery may represent endometritis.
* **Pyometra** (pus within the uterus) is very rare and usually due to outflow obstruction. An evaluation of cervical malignancy should be performed.
32
Intrauterine Devices (IUDs)
* US appearance
* Rare, but serious side-effects
* The ultrasound appearance of an intrauterine device is dependent on the type of IUD:
* Mirena IUD (delivers progesterone): Shadowing structure in the endometrial canal.
* Conventional IUD: Highly echogenic.
* Potential complications of an IUD are rare but serious:
* Increased risk of infection with prolonged IUd use, especially actinomycosis.
* When pregnancy occurs in the presence of an IUD, there is an increased risk for **ectopic pregnancy**.
* Uterine perforation is very rare.
33
Uterine arteriovenous malformations (AVMs)
* Causes
* US Appearance
* Uterine arteriovenous malformation may be congenital (very rare) or acquired iatrogenically (e.g., from a D&C).
* Grayscale and color Doppler appearance shows an enlarged, heterogeneous, and multicystic uterus. The appearance is similar to gestational trophoblastic disease but with negative beta-hCG.
34
Describe the post-cesarean section complications and their US appearances
Why is it important to differentiate them?
* **Bladder-flap** **hematoma** is a rare complication of a low-transverse Cesarean section, where a postsurgical hematoma forms in the **vesicouterine space** (posterior to the bladder, between the bladder and the uterus).
* Ultrasound of a bladder-flap hematoma will show a **complex mass posterior to the bladder.**
* **Subfascial** **hematoma** is also a rare complication of Cesarean section due to extraperitoneal hemorrhage within the **prevesical** **space** (anterior to the bladder).
* Ultrasound shows a **complex mass anterior to the bladder.**
* It is important to distinguish a subfascial hematoma from a bladder-flap hematoma as the **surgical approach for repair is different.**
35
Describe the anatomy of ovaries and adnexa
* There is a dual blood supply to the ovary:
* The ovarian artery comes directly off the aorta to supply the lateral aspect of the ovary.
* A branch of the uterine artery arises from the internal iliac artery to supply the medial aspect of the ovary.
* The fallopian tube is divided into four segments, from proximal to distal:
* Interstitial (intramural) is the narrowest segment.
* Isthmus.
* Ampulla.
* Infundibulum.
36
Describe all the cyclical changes within the ovaries
* **Day 5-7** of the menstrual cycle: multiple follicles become apparent in the ovary.
* **Day 8-13**: one (or more) dominant follicles arise.
* 4-5 days before ovulation, the dominant follicle grows at the rate of approximately 2-3 mm/day.
* The maximal diameter of the dominant follicle is approximately 2 cm.
* The day prior to ovulation, a hypoechoic ring forms around the dominant follicle, which represents the granulosa layer separating from the theca.
* **Day 14: ovulation**. Physiologic bleeding occurs into the follicle at the time of ovulation, at which point the follicle is called the corpus hemorrhagicum. After ovulation, the corpus hemorrhagicum becomes the corpus luteum.
* **Day 15-20**: The corpus luteum retains fluid over the next 4-5 days to reach a maximal size of approximately 3 cm.
* **Day 20-28**. If pregnancy doesn’t occur, the corpus luteum involutes to become the corpus albicans, which cannot be seen by ultrasound.
37
What happens to the ovarian cycle if pregnancy occurs?
* If pregnancy does occur, the corpus luteum develops into a gland secreting hCG. A prominent corpus luteum may be mistaken for an ectopic pregnancy due to its similar appearance. However, an ectopic pregnancy will only very rarely be in the ovary.
38
What is the ultrasound appearance of physiologic ovarian simple cyst?
* A simple ovarian cyst is a round or oval anechoic structure with smooth and imperceptibly thin walls, posterior acoustic enhancement, and lack of worrisome features such as solid components, septations, or internal flow on coloDopplerer.
* A simple ovarian cyst is a follicle that physiologically enlarges from estrogen stimulation as a normal part of the menstrual cycle.
39
What is the SRU consensus in premenopausal patients regarding simple ovarian cysts?
* Cysts \<3 cm do not need to be described in the report, and there is no need for follow-up.
* Cysts \>3 and
* Cysts \>5 and
* Cysts \>7 cm should be evaluated by MRI or surgery, as a full ultrasound assessment is difficult.
40
What is the SRU consensus in postmenopausal patients regarding simple ovarian cysts?
* Cysts \<1 cm do not need to be reported or followed.
* Cysts \>1 cm and =7 cm are almost certainly benign but should be described and followed annually with ultrasound (similar to premenopausal cysts \>5 and =7 cm).
* Cysts \>7 cm should be evaluated by MRI or surgery, as a full ultrasound assessment is difficult (similar to a premenopausal cyst of the same size).
The only difference is that is the cysts =5cm in a premenopausal patient do not need follow up, while in a postmenopausal patient a cyst \>/=1cm needs follow up.
41
What is a functional ovarian cyst and what kinds do they include?
* A functional cyst is the result of a follicular cycle that did not execute normally.
* Functional cysts include **follicular cysts, corpus luteal cysts, and theca-lutein cysts**.
42
What is a follicular cyst and what is the US appearance?
* A follicular cyst is a **simple cyst larger than 25 mm**, representing a follicle that did not undergo ovulation.
43
What are a corpus luteal cysts and its US appearance?
* A corpus luteal cyst may grow to greater than 3 cm if it fails to involute normally.
* A corpus luteal cyst can have variable appearances, but will often look like a complex ovarian cyst.
* High diastolic flow is often present, which can also be seen in ovarian cancer.
44
When can theca-lutein cysts be seen?
* Theca-lutein cysts are often multiple and arise from elevated hCG.
* They can be seen in molar pregnancy, multiple gestations, or infertility patients on gonadotropins or clomiphene.
45
What are hemorrhagic ovarian cysts and its US appearance (acutely and subacute)?
* A hemorrhagic cyst is the result of hemorrhage into a functional cyst, most commonly a corpus luteum. Ultrasound findings can be suggestive, although a complex cyst should be followed-up at least once to ensure resolution.
46
What is ovarian hyperstimulation syndrome (OHSS)?
US appearance?
Criteria?
What does OHSS increase the risk of?
* OHSS is a complication of fertility treatment, thought to be due to VEGF dysregulation causing capillary leak.
* The criteria for diagnosis of OHSS include abdominal pain, enlargement of the ovary to greater than 5 cm, and presence of either ascites or hydrothorax. At least one additional laboratory or clinical symptom must be met, including elevated hematocrit (\>45%), elevated WBC (\>15,000), elevated LFTs, acute renal failure, or dyspnea.
* OHSS increases the risk of ovarian torsion and ectopic pregnancy.
47
What is polycystic ovarian syndrome (PCOS)?
US appearance/criteria?
Give a potential differential consideration and contrast it to PCOS.
* PCOS is a clinical syndrome of obesity, insulin resistance, anovulation, and hirsutism secondary to excess androgens.
* Ultrasound criteria include **\>12 small follicles (most often arranged around the periphery of the ovary),** none greater than 9 mm in diameter, and an **ovarian volume \>10 mL**. Ovarian volume is calculated by multiplying the diameter of three orthogonal planes by 0.52.
* The ovarian stroma is typically very vascular when evaluated by color Doppler.
* A differential consideration is normal ovaries under the influence of oral contraceptives, although **contraceptives will not increase the vascularity of the ovary**.
48
What is a paraovarian cyst?
What is the main differential?
What is considered a normal size for paraovarian cyst?
* A paraovarian cyst is a simple cyst separate from the ovary, thought to be developmental in origin.
* Paraovarian cysts are considered normal if \<5 cm.
* The main differential is an ovarian cyst. Ovarian cysts should be reported (and followed) if they are greater than 3 cm, while paraovarian cysts do not need to be followed unless they are greater than 5 cm.
49
What is a peritoneal inclusion cyst?
Treatment?
What is the main differential?
* A peritoneal inclusion cyst is a septated fluid collection formed by adhesions from prior surgery. The ovary is always closely associated with the peritoneal inclusion cyst, either trapped within or adjacent to it.
* It is important not to recommend surgery for treatment of a peritoneal inclusion cyst, as further surgery may create additional adhesions.
* The main differential of a peritoneal inclusion cyst is a cystadenoma, which has thick septations and tends to exert mass effect.
50
Give three reasons why a fallopian tube may become distended
* The fallopian tube may become distended due to **infection, inflammation, or traction** from pelvic adhesions.
51
What is a hydrosalpinx?
US appearance?
* A hydrosalpinx is a fluid-filled fallopian tube lacking internal echoes. Ultrasound shows a dilated, anechoic, paraovarian tubular structure with incomplete septations. The incomplete septations represent infoldings of the tubular walls.
52
What is a hematosalpinx?
US appearance?
* Hematosalpinx is a blood-filled fallopian tube that can be seen in the setting of a ruptured ectopic pregnancy or endometriosis. Imaging will show **internal echoes within the dilated tube.**
53
What is a pyosalpinx?
US appearance?
* Pyosalpinx is a pus-filled fallopian tube resulting from pelvic inflammatory disease. As in hematosalpinx, imaging will show **internal echoes within the dilated tube.**
54
What is adnexal torsion and how does it present?
Epidemiology? Which side is more common?
What does torsion mimic?
* Adnexal torsion results from twisting of the ovarian vascular pedicle. This results in pain and potential vascular compromise to the ovary.
* **Acute pain** is usually localized to the affected side. Pain may be episodic, especially if the torsion is intermittent. Torsion occurs mainly in reproductive-age women, and commonly occurs in pregnancy. Torsion occurs more commonly on the right side due to the position of the sigmoid colon, which inhibits free rotation of the left adnexa. Torsion may clinically mimic appendicitis.
55
What predisposes one to adnexal torsion?
* The ovary may be predisposed to torsion by a **lead-point mass**, most commonly a **dermoid**.
56
Describe the US appearance/findings in adnexal torsion
* Because of the dual blood supply to the ovary (lateral from the ovarian vessels off the aorta, and medial from the uterine vessels from the internal iliac), **flow** **may still be detectable** by color doppler even with torsion.
* The classic ultrasound presentation of torsion in a patient with acute pelvic pain is an **enlarged ovary with free fluid and abnormal ovarian doppler. The vascular pedicle may be twisted**, which is very specific when seen.
* Less specific but more common findings include:
* Enlarged ovary \>4 cm in diameter.
* Unusual position of the affected ovary, which may even be found on the contralateral side.
* Follicles pushed to the periphery of the ovary.
* Free fluid in the pelvis.
* variable doppler findings: Complete lack of flow is concerning, although this is rarely seen. Other Doppler findings include intermittent flow, venous flow on spectral imaging, and even normal flow.
57
What is a dermoid cyst?
What is another name for dermoid cysts?
US appearance?
How to confirm?
* Dermoid cyst, also called a **mature cystic teratoma**, is the most common ovarian neoplasm. Technically, a teratoma contains all three primitive germ cell layers, while a dermoid cyst may contain only two. In general use, however, these terms are interchangeable.
* Dermoid cysts are benign. malignant transformation is very rare and typically occurs in postmenopausal patients.
* The classic ultrasound appearance of a dermoid cyst is a complex ovarian cyst with an echogenic **Rokitansky nodule**, a mural nodule containing solid elements. The imaging appearance can be variable, however, and other common imaging features include:
* The **dot-dash pattern** describes interrupted echogenic lines thought to be produced by keratin fibers.
* The tip of the **iceberg sign** describes obscuration of the deeper contents due to high-attenuation material.
* In ambigious cases confirm presence of **fat** with CT or MR.
58
What are the US findings suggestive of an ovarian malignant mass?
* High **F**low on Doppler
* **M**ural nodule
* Thick or irregular **W**alls or septae
* Presence of **A**scites
* **S**olid components
* **P**apillary projections
MNEMONIC: FM WASP
59
What are the three primary histologic types of ovarian neoplasms?
* Epithelial neoplasm (comprises two-thirds of all ovarian neoplasms)
* Germ cell tumor
* Sex cord-stromal tumor
60
What are the four subtypes of epithelial ovarian neoplasms?
* The three subtypes of epithelial neoplasm are serous and mucinous cystadenocarcinomas, and endometrioid (may arise from endometriosis) and Brenner tumor.
61
What are the sex cord-stromal tumors?
* Granulosa-theca cell tumors - often produces estrogen (may cause endometrial carcinoma)
* Sertoli-Leydig cell tumor - may produce androgen. Characteristic path = Reinke crystals
* Fibroma - benign tumor of fibroblasts. Can leads to Meig's syndrome.
62
What is a Brenner tumor?
* Ovarian epithelial tumor composed of bladder-like epithelium
* Usually benign.
63
What is Meig's syndrome?
* Meigs syndrome is the triad of **benign ovarian fibroma, ascites, and right pleural effusion.**
64
What is Struma ovarii?
* Struma ovarii is a subtype of teratoma that is composed of mature, functioning thyroid tissue that can lead to hyperthyroidism.
65
What are the subtypes of ovarian germ cell tumors?
Tumor subtypes mimic tissues normally produced by germ cells
* Oocytes - dysgerminoma
* Fetal tissue - embryonal carcinoma and cystic teratoma
* Yolk sack - endodermal sinus tumor (elevated AFP)
* Placental tissue - choriocarcinoma (elevated b-HCG)
This reflects same thing in males! (ie seminoma and NSGCTs)
66
DDx for Endometrial Cysts
* The differential diagnosis of endometrial cysts includes
* hemorrhagic functional cysts
* fibrothecoma
* cystic mature teratoma
* cystic ovarian neoplasm
* ovarian abscess.
