Ultrasound Evaluation of the Adnexae. A Practical Approach

 

Ultrasound Evaluation of the Adnexae

INTRODUCTION

Ultrasound is the preferred imaging modality for the assessment of the pelvis and in particular

the uterus and the ovaries for the presence of pathology. Advantages that ultrasound has over

other imaging modalities, such as Computed Tomography and Magnetic Resonance Imaging, are

obvious and includes the lower cost of ultrasound, its bedside portability, and the ability of the

transvaginal ultrasound transducer to obtain high resolution images which allow for outstanding

detailed anatomic evaluation of the pelvic organs. Furthermore, the transvaginal ultrasound

transducer can be used by the examiner as an extension of the gynecologic examination and thus

can help in correlating the patient’s symptoms with the exact anatomic location on ultrasound.

The use of color and pulsed Doppler can also be added to assess the vascularity of tissue, which

may help in the characterization of some adnexal masses. The presence of an abnormal adnexal

mass should be evaluated by ultrasound in details. The relationship of the adnexal mass to the

ovary and or the uterus should be assessed and the possibility of malignancy should be evaluated.

THE NORMAL OVARY

The most optimal approach to assess the ovaries on ultrasound is the transvaginal approach using

the transvaginal ultrasound transducer as it allows for the best resolution of morphologic details.

The transvaginal approach is best performed with an empty bladder. The transabdominal

approach, which should be reserved for situations where the transvaginal approach is not

feasible, is a limited approach to the evaluation of the ovaries due to the lower resolution of the

abdominal ultrasound transducers and the presence of bowel loops, which often shadow the

ovaries in the pelvis.

The normal ovary is relatively easy to detect in the reproductive years. The presence of ovarian

follicles (Figure 12.1), or a corpus luteum, serves to differentiate the ovary from surrounding

tissue in the pelvis on ultrasound. The normal ovary’s typical anatomic location in the pelvis is

lateral to the broad ligament and overlying the hypogastric vein (Figure 12.2). Bowel peristalsis

helps to differentiate between moveable structures and the static ovary. The authors recommend

the following steps for the localization of the normal ovaries by transvaginal ultrasound:

ULTRASOUND EVALUATION

OF THE ADNEXAE

Figure 12.1: Transvaginal ultrasound of a normal ovary. Note the presence

of multiple ovarian follicles (arrows) that help to differentiate the ovary

from surrounding tissue. Image is courtesy of Dr. Bernard Benoit.

Figure 12.2: Transvaginal ultrasound of a normal ovary (labeled). Note the

anatomic location of the ovary, overlying the hypogastric vein (labeled as

vessel).

Step One: Insert the transvaginal transducer and obtain a mid-sagittal plane of the uterus (Figure

12.3).

Step Two: Rotate the transvaginal transducer ninety degrees and obtain a transverse plane of the

uterus at the level of the fundus (Figure 12.4). Ensure that the transverse plane is at the level of

the fundus and not at the uterine isthmus.

Figure 12.3: Transvaginal ultrasound of the mid-sagittal plane of the

uterus. For more details on ultrasound imaging of the uterus, refer to

chapter 11.

Figure 12.4: Transvaginal ultrasound of the transverse plane of the uterus,

obtained by rotating the transducer 90 degrees from the midsagittal plane

(see Figure 12.3). For more details on ultrasound imaging of the uterus,

refer to Chapter 11.

Step Three: While maintaining the transverse orientation, angle your probe towards the right

side of the patient, looking for the right ovary – (the handle of the transducer should get close or

touch the patient’s left inner thigh). Follow the right ovarian ligament as it commonly leads you

to the anatomic location of the right ovary (Figures 12.5 and 12.6). The right ovary should come

into view overlying the right hypogastric vein (Figure 12.2). Repeat the same maneuver for the

left side. Clip 12.1 shows a movie of these suggested steps.

The size of the normal ovary varies slightly with the time of the menstrual cycle as well as the

woman’s age. The ovary should be measured on ultrasound in 3 dimensions; width, length and

depth on views obtained in 2 orthogonal planes (Figure 12.7 A and B). The ovary appears ovoid

(like a chicken egg) in shape and typically contains numerous follicles especially in the

reproductive years (see Figure 12.1). The ovaries may not be identifiable in some women. This

occurs most frequently prior to puberty, after menopause, or in the presence of large uterine

fibroids, which shadow the adnexal regions. If a woman has undergone hysterectomy, the ovaries

are typically more difficult to image by ultrasound because the bowel fills the space left by the

removal of the uterus, and makes ultrasound imaging less optimal. The normal fallopian tubes

are not commonly identified as separate structures on ultrasound unless they have pathology.

Figure 12.5: Transvaginal ultrasound of the uterus in transverse orientation looking for

the right ovary. Note that if you follow the ovarian ligament (labeled), this commonly

leads you to the ipsilateral ovary.

Figure 12.7 A and B: Transvaginal ultrasound showing the measurement of an ovary in its 3

dimensions; length in A and width (measurement 1 on figure B) and depth (measurement 2

on figure B). Figures A and B are orthogonal planes. Image is courtesy of Dr. Bernard Benoit.

Figure 12.6: Transvaginal ultrasound of the uterus in transverse orientation showing the

ovarian ligament and the ovary. Note the relationship between the transverse plane of the

uterus (uterus), the ovarian ligament and the ovary (both labeled). By following the ovarian

ligament, the ovary can commonly be seen. See text for details.

Table 12.1 lists benign adnexal masses that are commonly encountered in women of

reproductive age. Detailed sonographic characteristics of these masses are discussed in the

following sections.

SIMPLE CYST

Characteristics of a simple ovarian cyst on ultrasound include a thin well-rounded capsule with

smooth wall and excellent sound transmission (Figure 12.8). There should be no internal

irregularities on the capsule wall and no internal papillary projections (Figure 12.8). The cyst

content should be anechoic with no reflection of echo, which typically suggests clarity of the

fluid (Figure 12.8). The presence of recognized ovarian tissue on ultrasound in the capsule of the

cyst is a normal finding (Figure 12.8). The presence of septations or papillary projections within

a cyst (Figure 12.9) may represent signs of malignancy and thus should warrant a referral to an

experienced sonographer or sonologist for further evaluation of the adnexae.

TABLE 12.1 Common Benign Adnexal Masses in Reproductive Age Group

- Simple Cyst - Hemorrhagic Cyst

- Endometrioma - Dermoid Cyst

- Pedunculated leiomyoma - Hydrosalpinx

- Tubo-ovarian Abscess - Peritoneal Inclusion Cyst

Figure 12.8: Transvaginal ultrasound of a simple ovarian cyst. Note the presence of a thin

round, smooth capsule (labeled) with no papillary projections and with excellent sound

transmission. Note the presence of ovarian tissue (asterisk).

HEMORRHAGIC CYST

Hemorrhagic cyst, also commonly referred to as hemorrhagic corpus luteum, results from

bleeding inside an ovarian cyst. The event is typically noticeable by the woman and is described

as an acute pain in the right or left lower quadrant of the abdomen. The hemorrhagic cyst

typically goes through a temporal pattern of clot formation within the cyst, clot lysis, clot

retraction and clot resolution. The sonographic appearance of the hemorrhagic cyst is thus

dependent on the stage of evolution of the cyst’s content. Given that hemorrhagic cysts present in

symptomatic women and that the sonographic appearance on ultrasound resembles a “solid

appearing adnexal mass” at some phases of development, it is a common reasons for unnecessary

pelvic surgery.

In its early stages, hemorrhagic cysts appear as solid masses with smooth thin walls and excellent

sound transmission (Figure 12.10). The cyst content has variable echogenicity with

characteristic thin linear reticular strands (Figure 12-10). Upon follow-up, blood clot retracts

within the hemorrhagic cyst and a fluid layer develops within the cyst itself, resulting in another

sonographic characteristic of a hemorrhagic cyst (Figure 12.11). At a point of clot retraction, the

clot may appear like a papillary projection within the cyst (Figure 12.12). It is important to make

Figure 12.9: Transvaginal ultrasound of a left adnexal mass. Note

the presence of papillary projections (arrows), which may

suggest the presence of malignancy and thus requires referral to

experienced sonography.

the distinction between a retracted blood clot and a papillary projection resulting from a

malignant growth. We propose several differentiating features:

Figure 12.10: Transvaginal ultrasound of a hemorrhagic cyst. Note

the solid appearance with smooth capsule (labeled) and excellent

sound transmission (big arrows). Note the variable echogenicity

and the characteristic thin linear reticular strands (small arrows).

Figure 12.11: Transvaginal ultrasound follow-up of the

hemorrhagic cyst in figure 12.10. Note the retraction of the blood

clot (asterisk) with the development of a fluid layer.Chapter 12: Ultrasound Evaluation of the Adnexae 261

1) A blood clot within an ovary (hemorrhagic cyst) should never have any capillary flow

within it on color Doppler sonography. We therefore recommend the placement of color

Doppler sonography (using low velocity scale, around 5-10 cm/sec and low filter

settings) on all adnexal masses to assess for capillary flow. The absence of capillary flow

within an adnexal mass with the sonographic appearance of a hemorrhagic cyst confirms

its diagnosis (Figure 12.13). The presence of capillary flow within the content of an

adnexal mass (Figure 12.14) on the other hand, is not compatible with a hemorrhagic

cyst and should be referred to expert sonography for further evaluation.

Figure 12.12: Transvaginal ultrasound of a hemorrhagic cyst with

blood retraction. Note the appearance of the retracted blood clot

(labeled), similar to a papillary projection. Read text for

differentiating features between a retracted clot and a papillary

projection.Chapter 12: Ultrasound Evaluation of the Adnexae 262

Figure 12.13: Transvaginal ultrasound with color Doppler of the hemorrhagic cyst in figure

12.11. Note the retraction of the blood clot (asterisk) with the development of a fluid layer.

Color Doppler shows vascular flow in the capsule (labeled) but none within the blood clot

(arrows).

Figure 12.14: Transvaginal ultrasound with color Doppler of an ovarian cancer. Note the

presence of multiple papillary projections. Color Doppler shows vascular flow within the

papillary projections (arrows).Chapter 12: Ultrasound Evaluation of the Adnexae 263

2) A blood clot within a hemorrhagic cyst tends to jiggle when probed by the transvaginal

ultrasound transducer (Clip 12.2). Use this technique to confirm the content of a

hemorrhagic cyst.

3) Blood clots within hemorrhagic cysts also tend to have broad bases (Figure 12.12) and

the content tends to shift with patient repositioning.

4) The blood clot retraction typically results in a single mass of clotted blood within the cyst

(Figure 12.12). The presence of multiple papillary projections (Figure 12.14) within a

cyst therefore is more compatible with a neoplastic process.

5) Follow-up examination is also one of the most important tools to help in the

differentiation. Given the important temporal change of hemorrhagic cysts; a follow-up

ultrasound examination within 4-6 weeks should help in differentiating a hemorrhagic

cyst from a borderline or malignant tumor. Hemorrhagic cysts tend to resolve and regress

with time whereas solid adnexal masses of malignant origin tend to grow. Table 12.2

lists the characteristics of a hemorrhagic ovarian cyst.

ENDOMETRIOMAS

Endometriomas are thin walled “solid” appearing ovarian masses that are typically unilocular

and have a characteristic “ground glass” appearance (Figure 12.15). They are commonly

homogeneous and have low-level echoes with excellent sound transmission (Figure 12.16).

Hyperechoic foci are commonly seen within endometriomas and are sometimes referred to as

calcific stippling (Figure 12.17). 

Unlike hemorrhagic cysts, the sonographic appearance of

endometriomas tends to remain stable over time. An endometrioma should not have any blood

vessels within its content. The application of color Doppler at low velocity scales, around 5-10

cm / sec with low filter settings, for the demonstration of absence of vascularity within the

endometrioma, is therefore an essential component of the diagnosis (Figure 12.15 and 12.18).

The presence of vascularity on color Doppler in the setting of an endometrioma-like mass

TABLE 12.2 Characteristics of an Ovarian Hemorrhagic Cyst

- Excellent sound transmission

- Thin Reticular lacy pattern

- Temporal changes

- Solid – Fluid level

- Jiggles when probed

- Absence of vascular signals on low-velocity color Doppler

- Single mass of clotted blood when retracted

- Follow-up shows resolution

(Figure 12.19) should raise suspicion for malignancy (endometrioid tumor) and a referral to

expert sonography should be immediately performed. Table 12.3 lists the sonographic

characteristics of endometriomas.

Figure 12.15: Transvaginal ultrasound with color Doppler of an endometrioma showing a

unilocular mass with ground glass appearance. Note the absence of vascularity within the

content of the mass on low velocity scale (5 cm/sec) color Doppler.

Figure 12.16: Transvaginal ultrasound of an endometrioma showing a unilocular mass with

ground glass appearance and excellent sound transmission (arrows).

Figure 12.17: Transvaginal ultrasound of an endometrioma showing a unilocular mass with

ground glass appearance. Note the presence of hyperechoic foci (arrows) that are also

referred to as calcific stippling.

Figure 12.18: Transvaginal ultrasound with color Doppler of an endometrioma showing the

absence of vascularity within the content of the mass on low-velocity color Doppler. Vascular

flow can be demonstrated in the capsule (labeled).

TABLE 12.3 Sonographic Characteristics of Endometriomas

- Excellent sound transmission

- Homogeneous, ground glass appearance

- Typically unilocular

- No or minimal temporal changes

- Hyperechoic foci

- Absence of vascular signals on low-velocity, low-filter color Doppler

settings

Figure 12.19: Transvaginal ultrasound with color Doppler of a solid

mass that appeared similar to an endometrioma on grey scale

imaging. Note the presence of extensive vascularity within the solid

component (arrows). Pathologic examination revealed an

endometrioid ovarian cancer.

DERMOID CYST (MATURE CYSTIC TERATOMA)

Dermoid cysts, or mature cystic teratomas, originate from the ovarian germ cells. They affect

younger age groups than epithelial tumors, are slow growing and are bilateral in about 10 % of

cases. The most common sonographic appearance of a dermoid cyst is a complex, cystic and

solid mass, with echogenic internal content that shadows extensively resulting in a “tip of the

iceberg” effect (Figure 12.20). Characteristic features on ultrasound include a white echogenic

“ball” which typically corresponds to the sebum and hair content of the dermoid, long and short

echogenic linear strands which correspond to the hair in the fluid content of the cystic

components, and significant attenuation of sound (Figure 12.21 A and B). The white echogenic

ball is referred to as the Rokitansky nodule or dermoid plug (Figure 12.21 A and B). Dermoid

cysts may be small and located within the ovary (Figure 12.22) or may assume different shapes

and sizes (Figure 12.23 A and B). They tend to be located superiorly in the pelvis and thus on

occasions may be outside the reach of the transvaginal transducer. The presence of excessive

papillary projections within a dermoid cyst, in addition to the presence of vascularity on color

Doppler evaluation, (Figure 12.24) should raise the suspicion for the presence of immature or

neuronal elements within and thus appropriate referrals should be made. Table 12.4 lists the

sonographic characteristics of dermoid cysts.

Figure 12.20: Transvaginal ultrasound of a dermoid cyst. Note the complex, cystic

and solid content (labeled) with extensive shadowing (arrows). This has been

compared to the “tip of the iceberg”. See text for details

Figure 12.21 A and B: Transvaginal ultrasound of dermoid cyst A and B. Note the white

echogenic “ball” (Rokitansky nodule) in A and B (asterisk). Note the long and short echogenic

linear strands, which correspond to the hair content (arrows).

Figure 12.22: Transvaginal ultrasound with color Doppler of a small dermoid (arrows),

located within the ovary.

TABLE 12.4 Sonographic Characteristics of Dermoid Cysts

- Poor sound transmission (tip of iceberg effect)

- Complex, solid-cystic tumors, heterogeneous content

- White echogenic ball (Rokitansky nodule)

- Thin linear strands

- Superior location in pelvis

- Absence of vascular signals on low-velocity, low-filter, color Doppler

settings

Figure 12.23 A and B: Transvaginal ultrasound of dermoid cysts in A and B. The dermoid cysts

are labeled in A and B. The arrows point to normal ovarian tissue. In B, the dermoid is cystic

with echogenic foci corresponding to the fat content within the fluid.

Figure 12.24: Transvaginal ultrasound with color Doppler of an immature teratoma

with neuronal elements. Note the presence of papillary projections with vascularity

noted on color Doppler.

PEDUNCULATED LEIOMYOMA – OVARIAN FIBROMA

Pedunculated leiomyomas are included in this chapter as they typically present as solid adnexal

masses with extensive shadowing (Figure 12.25) and are commonly associated with a vascular

pedicle that can be traced by color Doppler to the uterus. They are commonly round or oval with

a regular striped echogenicity. Leiomyomas display a characteristic shadow pattern of the

ultrasound beam described as “venetian blinds shadowing” (blinds that are partially open with

the sun rays coming through) (Figure 12.25). This shadowing pattern is present in most

leiomyomas and helps differentiate leiomyomas from other solid tumors. Identifying a separate

normal ovary in the adnexal region, when a pedunculated leiomyoma is suspected, helps in

confirming the diagnosis. The ovary should be freely movable and separate from the

pedunculated leiomyoma thus insuring that the leiomyoma and the ovary are not anatomically

attached (Clip 11.1). Table 12.5 lists the sonographic characteristics of pedunculated

leiomyomas. For more detailed discussion on leiomyomas, please refer to chapter 11.

An ovarian fibroma is a solid tumor that arises from the ovary and it shares several of the

sonographic characteristics of a pedunculated leiomyoma (Figure 12.26). The ovarian fibroma

however is an ovarian tumor and thus is not freely movable in the adnexa as it is attached to the

ovary (Clip 12.3).

Figure 12.25: Transvaginal ultrasound of a pedunculated leiomyoma with the characteristic

“venetian blinds shadowing” (dashed arrows). Note the extensive shadowing (labeled) on the

posterior aspect of the leiomyoma.

HYDROSALPINX

The normal fallopian tube is rarely seen on transvaginal ultrasound. When the tube is filled with

fluid however, it is easily seen as a fluid-filled sausage-shaped structure, with thin walls,

incomplete septations (Figure 12.27), and a cogwheel appearance on cross section. There is lack

of peristalsis, a feature that differentiates the elongated fluid filled structure from bowel.

Furthermore, the hydrosalpinx, with its elongated sausage-shaped structure tends to taper near its

uterine origin. The presence of a tubular structure filled with clear fluid in the adnexal region

should raise suspicion for a hydrosalpinx, especially when a separate ovary is seen.

Figure 12.26: Transvaginal ultrasound of an ovarian fibroma. Note the characteristic

“venetian blinds shadowing” (dashed arrows). The fibroma is attached to the ovary and

does not move freely in the adnexa. See Clip 12-3 for details.

TABLE 12.5 Sonographic Characteristics of Pedunculated Leiomyomas

- Poor sound transmission

- Solid tumors, regular striped echogenicity

- Vascular pedicle to the uterus

- “Venetian blinds shadowing”

- Separate freely movable ovary

Hydrosalpinges are typically asymptomatic and are commonly seen in postmenopausal women.

If the diagnosis of a hydrosalpinx is entertained, a follow-up ultrasound is helpful, as it typically

shows no sonographic change in appearance. The application of three-dimensional ultrasound in

inverse mode, if available, can confirm the diagnosis (Figure 12.28). Table 12.6 lists the

sonographic characteristics of a hydrosalpinx.

Figure 12.27: Transvaginal ultrasound of a hydrosalpinx. Note the presence of a tubular

structure with thin walls and multiple septations.

TUBO-OVARIAN ABSCESS

A tubo-ovarian abscess occurs when an ascending infection involves the tube and ovary as part

of an acute process. Women are typically symptomatic with fever and pelvic pain and

tenderness, but on occasions tubo-ovarian abscesses may be silent. The ultrasound characteristics

include a multilocular mass with thick walls and thick incomplete septae that are filled with an

echogenic fluid of ground glass appearance (Figure 12.29). 

TABLE 12.6 Sonographic Characteristics of Hydrosalpinges

- Fluid filled, sausage shaped structure

- Structure tapers near the uterine origin

- Thin walls

- Multiple and incomplete septations

- Absence of peristalsis

- Cogwheel appearance on cross section

Figure 12.28: Three-dimensional ultrasound in inverse mode of the cystic mass in figure

12.26. Note the display on 3D of a folded tubular structure confirming the diagnosis of

hydrosalpinx.

The fluid content derives from the

inflammatory process. The sonographic appearance may be similar to endometriomas, but

endometriomas are more commonly unilocular in asymptomatic women and do not have

incomplete septations. Differentiating a tubo-ovarian abscess from other pelvic abscesses may be

difficult. The involvement of the ovary in the process is helpful in that differentiation. Table

12.7 lists the sonographic characteristics of tubo-ovarian abscesses.

PERITONEAL INCLUSION CYSTS

Peritoneal inclusion cysts also referred to, as pseudocysts are cystic structures within the pelvis

that entraps peritoneal fluid. 

TABLE 12.7 Sonographic Characteristics of Tubo-Ovarian Abscesses

- Multilocular mass with thick walls

- Thick incomplete septae

- Fluid content is echogenic, with ground-glass appearance

- Involvement of the ovary

Figure 12.29: Transvaginal ultrasound of a tubo-ovarian abscess (TOA). Note the ovoid shape

of the TOA, with thickened walls and septations (asterisks). The uterus (labeled) is noted

adjacent to the TOA.

These cysts primarily occur following pelvic surgery or infection and result from pelvic adhesions that entrap fluid. Ultrasound characteristics include multiple

primarily thin (Clip 12.4), but occasionally thick septations that attach to pelvic organs such as

the uterus, bowel and ovaries (Figure 12.30). The fluid content is typically clear and normal

looking ovaries can be seen on occasions, which confirm the diagnosis (Figure 12.30).

Peritoneal inclusion cysts are typically asymptomatic and women are commonly referred with

the finding of a septated pelvic mass diagnosed on CT scan or Magnetic Resonance Imaging

(MRI). Inquiring about the patient’s surgical history is important, as pelvic adhesion from prior

pelvic surgery is an etiological factor for peritoneal inclusion cysts. Table 12.8 lists the

sonographic characteristics of peritoneal inclusion cysts.

TABLE 12.8 Sonographic Characteristics of Peritoneal Inclusion Cysts

- Multiple primarily thin septations

- Septations attach to pelvic organs

- Fluid within the cysts is primarily clear

- Normal looking ovaries can be occasionally seen

Figure 12.30: Transvaginal ultrasound of peritoneal inclusion cysts. Note the presence of

multiple primarily thin septations (arrows) that entrap fluid and attach to pelvic organs such

as the uterus, bowel and ovary (labeled).

THE POLYCYSTIC OVARY

Polycystic ovary syndrome is a metabolic disorder that is characterized by menstrual disorders,

such as anovulation, hyperandrogenism, infertility and a spectrum of metabolic abnormalities.

The presence of polycystic ovaries, unilaterally or bilaterally, is part of the polycystic ovary

syndrome but having polycystic ovaries is not a requirement for diagnosis. The morphologic

criteria for the diagnosis of polycystic ovaries have changed throughout the years. Since 2003,

most investigators have used a threshold of 12 follicles (measuring 2-9 mm in diameter) per

ovary, with increased stromal echogenicity. An increase in ovarian volume at greater or equal to

10 ml has also been suggested. Recent data suggest a follicular number per ovary of 25 or greater

for the diagnosis of polycystic ovaries when transvaginal ultrasound is used (1) (Figure 12.31).

If transvaginal ultrasound is not available and transabdominal ultrasound is used, an ovarian

volume of 10 ml or greater is then recommended for diagnosis (1). Finally, the finding of

polycystic ovaries in ovulatory women not showing clinical or biochemical androgen excess may

be inconsequential, even though there is a suggestion that this may represent the milder end of

the polycystic ovary syndrome spectrum.

Figure 12.31: Transvaginal ultrasound of a polycystic ovary. The ovary is more spherical in

shape and has an increased number of follicles that are situated in the periphery of the ovary.

Note also the presence of increased stromal echogenicity.

BORDERLINE AND MALIGNANT ADNEXAL MASSES

Ultrasound evaluation of adnexal masses is primarily performed to differentiate benign from

malignant lesions. Several common benign adnexal masses have sonographic characteristics

(Tables 12.1 to 12.8) that allow the examiner to make the diagnosis with near certainty.

Borderline and malignant adnexal masses also have certain characteristics that allow for a high

index of suspicion. Sonographic characteristics of malignant adnexal masses are listed in Table

12.9 and include irregularities in the capsule, thick septations, solid papillary projections (2) and

vascularity seen on color Doppler evaluation. Purely cystic masses that are unilocular or even

multilocular are overall benign with the exception of a large number of septae, which correlates

with borderline mucinous tumors.

The use of pulsed Doppler in the evaluation of adnexal masses has been shown to be inaccurate

due to high degree of overlap between benign and malignant masses, especially in

premenopausal women (3). In postmenopausal women where ovarian angiogenesis is

nonexistent, pulsed Doppler evaluation, looking for low impedance circulation and timedaverage maximum velocity, has some predictive value (4). In the authors’ experience, pattern

recognition of grey scale ultrasound is still the most important in differentiating benign from

malignant masses and the use of color and pulsed Doppler are adjuncts to grey scale evaluation.

Figures 12.32 to 12.36 show some borderline and malignant adnexal masses.

TABLE 12.9 Sonographic Characteristics of Borderline and Malignant Adnexal Masses

- Irregularities in capsule and content

- Thick septations

- Solid content

- Papillary projections

- Vascularity on color Doppler

Figure 12.32: Transvaginal ultrasound of a borderline serous cystadenocarcinoma. Note the

presence of papillary projections (arrows) in a small cystic mass.

Figure 12.33: Transvaginal ultrasound with high definition color of a borderline

mucinous cystadenocarcinoma. Note the presence of multiple thick septations with

vascularity noted on high definition color Doppler.

Figure 12.34 A and B: Transvaginal ultrasound of serous cystadenocarcinoma of the ovary. Note the

presence of multiple papillary projections in A (arrows) and in B, color and pulsed Doppler shows

vascularity within the papillary projections.

Figure 12.35 A and B: Transvaginal ultrasound of an endometrioid carcinoma of the ovary. Note the presence of

a solid mass with thick septations in A and vascularity with low impedance flow in B on color and pulsed Doppler

ultrasound.

ADNEXAL TORSION

Patients presenting with an adnexal torsion are typically symptomatic with acute pelvic pain and

tenderness. It is a common gynecologic presentation in the emergency department. Although

there are sonographic signs suggestive of the presence of adnexal torsion, ultrasound is not

diagnostic of such entity and a high suspicion should occur based upon the presenting symptoms

of the patient. Torsion results in obstruction of lymphatic and venous drainage of the ovary and

tube and thus is commonly associated with an enlarged, edematous adnexal mass. Hemorrhagic

infarction may occur and result in the presence of fluid with varying degrees of echogenicity.

Color and Doppler ultrasound does not confirm or rule out the diagnosis, as significant variations

with vascular occlusions exist. Intraperitoneal fluid may be present and is thought to result from

transudate from the capsule of the ovary with lymphatic and venous obstruction. Table 12.10

lists the sonographic characteristics of adnexal torsion.

Figure 12.36: Transvaginal ultrasound of a serous cystadenocarcinoma of the ovary. Note the

presence of papillary projections with vascularity noted on color Doppler.

PREDICTION MODELS FOR OVARIAN CANCER

Several models have been developed to characterize adnexal masses on ultrasound in order to

improve differentiation between benign and malignant tumors (5-7). One of the most widely

used classification method is that by the International Ovarian Tumor Analysis (IOTA) (8).

IOTA is a collaborative that standardized the approach to the ultrasound description of adnexal

pathology (8). 

A prospectively collected large database tested prediction models like the IOTA

risk of malignancy index (RMI) and showed excellent consistency and predictability of

malignant pathology. Their test performance almost matches subjective assessment by

experienced examiners, which is accepted to be the best way to classify adnexal masses prior to

surgery. 

Simple rules, many of which have been discussed in this chapter, can be applied to

classify tumors into benign or malignant (Figure 12.37). Alternatively, a logistic regression

model can be adopted for that purpose. For more information on the IOTA classification, the

readers are encouraged to review reference 8 in this chapter. Acquiring the expertise in the

subjective ultrasound evaluation of adnexal masses, on the other hand, provides excellent

differentiation between benign and malignant adnexal pathology.

TABLE 12.10 Sonographic Characteristics of Adnexal Torsion

- Enlarged edematous adnexal mass

- Cystic areas within the mass with varying degrees of echogenicity

- Tender mass on probing with the transvaginal transducer

Figure 12.37: Ultrasound features used in the International Ovarian Tumor Analysis (IOTA)

simple rules, illustrated by ultrasound images. B1–B5, benign features; M1–M5, malignant

features. Reproduced with permission from reference 8.

CLIP 12.1

CLIP 12.2Chapter 12: Ultrasound Evaluation of the Adnexae 284

CLIP 12.3

CLIP 12.4Chapter 12: Ultrasound Evaluation of the Adnexae 285

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