Ovaries and Adnexa

Ovaries and Adnexa

31.1 Simple Ovarian Cysts

Description and Clinical Features

The normal ovary in premenopausal women typically contains small cysts, less than 3 cm in diameter, representing follicles or functional cysts. Larger cysts, those greater than 3 cm, sometimes develop in the ovary. These cysts may represent unusually large follicles, nonfunctional ovarian cysts, or a cystic neoplasm of the ovary. Simple cysts are virtually always benign ovarian lesions. Except for a cystic neoplasm of the ovary, simple ovarian cysts tend to resolve on their own without intervention.

Very large, simple-appearing ovarian cysts, those measuring greater than 7 cm in diameter, may be difficult to evaluate completely by ultrasound. Further imaging with magnetic resonance imaging (MRI) or referral for surgical evaluation may be warranted for these very large cysts.

In postmenopausal women, simple cysts up to 1 cm in size are not uncommon and generally require no further assessment or follow-up. Simple cysts measuring between 1 cm and 7 cm, while most often benign, should undergo sonographic follow-up to resolution or until the cyst proves stable in size after 1–2 years. For simple cysts greater than 7 cm, MRI or surgical evaluation is often recommended.


A simple cyst of the ovary is an anechoic lesion with thin, smooth walls and enhanced through transmission (Figure 31.1.1). No blood flow should be detected within the cyst or its wall (Figure 31.1.2). Normal ovarian tissue is usually visible around a portion of the cyst, proving its intraovarian location.

Figure 31.1.1 Simple ovarian cyst. (A) Coronal (COR RO) and (B) sagittal (SAG RO) images of the right ovary demonstrating a simple ovarian cyst (arrows). Normal ovarian tissue (arrowheads) is seen around a portion of the cyst.

Figure 31.1.2 Simple ovarian cyst. A: Sagittal image of left ovary (SAG L) demonstrating a simple ovarian cyst (calipers) measuring 4.9 × 3.3 cm. B: Color Doppler image of cyst showing no internal blood flow nor flow in the thin, smooth wall of the cyst. No normal ovarian tissue is seen, but the most likely diagnosis is ovarian cyst.

31.2 Hemorrhagic Ovarian Cysts

Description and Clinical Features

A hemorrhagic ovarian cyst results when a functional ovarian cyst bleeds into itself. Hemorrhagic cysts, like simple ovarian cysts, are benign lesions of the ovary that most often resolve spontaneously, without requiring surgical intervention. Occasionally, acute hemorrhage into a cyst will cause sudden onset of pelvic pain, and, rarely, a hemorrhagic cyst ruptures.

Hemorrhagic cysts typically occur in women of reproductive age and not in postmenopausal women.

Figure 31.2.1 Hemorrhagic ovarian cyst. A: Transvaginal panoramic view demonstrating complex right ovarian cyst (arrows) adjacent to a normal uterus (U) and left ovary (arrowhead). B: Magnified view of right hemorrhagic ovarian cyst (arrows) showing internal septations forming a reticular pattern throughout the cyst. The cyst wall is slightly thickened on one side (arrowheads).


Hemorrhagic cysts appear as complex ovarian lesions, often with fine septations that form a reticular pattern throughout the cyst (Figures 31.2.1 and 31.2.2). The pattern of septations
is sometimes described as web-like or lacy. The fluid within the cyst often contains scattered echoes. The walls of a hemorrhagic cyst may be thin and smooth, or they may be focally or diffusely thickened. There is typically no blood flow seen within the cyst or in its septations, but flow may be seen in its outer walls (Figure 31.2.2).

Figure 31.2.2 Hemorrhagic cyst with blood flow in the wall. A: Coronal image of left ovary (COR LO) demonstrating a hemorrhagic cyst with echoes in the fluid of the cyst (arrow) and focal thickening of the wall (arrowheads). B: Color Doppler image showing circumferential flow in the cyst wall (arrows) and no flow in the septations or within the cyst.

The appearance of a hemorrhagic cyst typically evolves after the initial hemorrhage. With time, after the initial reticular pattern, the echoes within the cyst may conglomerate to one side of the cyst (Figure 31.2.3), sometimes with a concave contour. The conglomeration represents retracting clot. With continued involution, the cyst decreases in size and the septations and conglomeration of echoes become smaller or disappear (Figure 31.2.4).

Figure 31.2.3 Hemorrhagic cyst with retracting clot. Sagittal image of left ovary (SAG LT) showing a cyst (arrows) with septations, a solid-appearing component anteriorly (arrowheads), and anechoic fluid posteriorly.

Figure 31.2.4 Evolving hemorrhagic cyst. A: Image of ovary demonstrating a hemorrhagic cyst (arrows) with septations, echoes in the fluid, and blood flow in the wall. B: On follow-up scan 6 weeks later, the hemorrhagic cyst (arrows) is much smaller.

31.3 Ovarian Teratomas

Description and Clinical Features

The most common benign neoplasm of the ovary is a dermoid tumor, also called a mature cystic teratoma. This tumor is of germ cell origin and is often found in women of reproductive age. It is bilateral in 10% to 15% of cases. Most dermoid tumors are asymptomatic, but occasionally they cause lower abdominal pain, swelling, and irregular menses. Ovaries containing dermoids are at risk of torsion. If an ovarian mass with features suggestive of dermoid is detected, it is generally surgically excised. At pathology, the tumor may be found to contain fat and sometimes bone, teeth, or hair. Rarely, an ovarian teratoma is malignant.


Mature cystic teratomas (dermoid tumors) of the ovary often have a sonographic appearance that allows them to be differentiated from other ovarian neoplasms. One characteristic appearance is a complex, partially cystic mass in the ovary that contains one or more highly echogenic regions (Figure 31.3.1). Echogenic lines and dots (Figure 31.3.2) may be seen within the cystic areas of the mass, representing hair. Some of the highly echogenic regions represent fat within the tumor. The fat may be seen floating on top of other fluids in the lesion, leading to the sonographic finding of a fluid–fluid level (Figure 31.3.3). There may be echogenic regions with shadowing (Figure 31.3.4) or densely calcified structures representing teeth or bone. Dermoid tumors typically have little or no detectable internal flow on color Doppler imaging.

Figure 31.3.1 Ovarian dermoid tumors containing fat. (A) Coronal (COR R) and (B) sagittal (SAG RT) transvaginal images of mass (calipers) in right ovary filled with complex highly echogenic material, representing fat. (C) Coronal and (D) sagittal images of large mass (calipers) with lobular regions of increased echogenicity, representing fat, and regions of decreased echogenicity, representing fluid.

Figure 31.3.2 Ovarian dermoid tumor with echogenic lines and dots. Coronal image of left ovary (COR LT) demonstrating a dermoid tumor (calipers) with echogenic short lines and dots (arrows) within the cystic portion.

Figure 31.3.3 Ovarian dermoid tumor with fluid–fluid level. Sagittal image of right ovary (SAG RO) with complex lesion (calipers) containing hypoechoic and echogenic regions that form a linear interface (arrows) due to layering of fat and other fluid.

Figure 31.3.4 Ovarian dermoid tumor with highly echogenic solid nodule that shadows. A: Transvaginal image of ovarian mass (arrows) with a large shadowing nodule (arrowheads) protruding into the mass and causing an intense acoustic shadow (S). B: Sagittal image of ovarian mass (arrows) showing echogenic lines and dots (arrowheads) on the surface of the shadowing nodule.

31.4 Ovarian Benign Neoplasms Other Than Teratomas

Description and Clinical Features

Ovarian neoplasms that arise from epithelial cells and surrounding stromal cells can be malignant or benign. The most common benign neoplasms are mucinous or serous cystadenomas. Less common benign tumors arising from these cells include transitional cell (Brenner) tumors. Benign ovarian neoplasms can also arise from granulosa, theca, Sertoli, and Leydig cells. These neoplasms include ovarian fibromas, granulosa cell tumors, thecomas, and Sertoli–Leydig cell tumors.

Figure 31.4.1 Ovarian serous cystadenoma. A and B: Transvaginal color Doppler images of cystic ovarian lesion (arrows) with anechoic fluid and a few thin septations (arrowheads). Color Doppler shows blood flow within the septations.


Serous and mucinous cystadenomas of the ovary are typically complex ovarian lesions with septations separating areas of anechoic fluid (Figure 31.4.1). Modest blood flow can often be identified in the septations with color Doppler. Mucinous cystadenomas tend to have more septations than serous cystadenomas, and the fluid is more likely to contain low-level echoes (Figure 31.4.2). Some benign tumors are solid, such as fibroma (Figure 31.4.3) or thecoma. These tumors are typically homogeneous in echotexture and hypoechoic, sometimes causing acoustic shadowing, and their appearance may be similar to a uterine fibroid. Other benign tumors may contain both solid and cystic areas (Figures 31.4.4 and 31.4.5). In some benign cystic ovarian neoplasms, solid tumor nodules, with internal vascularity visible with color Doppler, are seen in the wall of the tumor (Figure 31.4.4), although this finding is more frequently seen with malignant than benign neoplasms.

Figure 31.4.2 Ovarian mucinous cystadenoma. (A) longitudinal and (B) color Doppler images of a right cystic mass (calipers and arrows) containing low-level echoes and a few thin septations (arrowheads). The fluid has different echogenicity in different components of the mass, typical of a mucinous cystadenoma.

Color Doppler is an important part of the sonographic evaluation of ovarian masses, because it provides information about the amount and location of blood flow within the

lesion. Spectral Doppler, however, is of limited value. While benign tumors tend to have high-resistance patterns of arterial flow, with a resistive index above 0.6 (Figure 31.4.5) or pulsatility index above 1.0, and malignant tumors often have low-resistance flow, with a resistive index below 0.4 or pulsatility index below 1.0, there is too much overlap in resistance patterns for spectral Doppler to differentiate benign from malignant lesions reliably.

Figure 31.4.3 Ovarian fibroma. (A) Sagittal (SAG RT) and (B) coronal (COR RT) images of the right ovary demonstrating a solid mass (arrows) with homogeneous echotexture and posterior shadowing. The mass has sonographic features similar to a uterine fibroid. C: Sagittal image of the uterus (SAG UT, arrows), which was completely separate from the ovarian mass in (A) and (B).

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Feb 2, 2020 | Posted by in GYNECOLOGY | Comments Off on Ovaries and Adnexa
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