From the Guidelines
In a vaginal ultrasound, a cyst typically appears as a well-defined, round or oval structure with smooth borders, and is usually filled with fluid, making it appear dark or anechoic (black) on the ultrasound image, with simple cysts being completely fluid-filled and appearing uniformly black with enhanced sound transmission behind them 1.
Characteristics of Cysts on Ultrasound
The appearance of a cyst on vaginal ultrasound can vary depending on the type of cyst.
- Simple cysts are completely fluid-filled and appear uniformly black with enhanced sound transmission behind them.
- Complex cysts may contain solid components, septations (internal walls), or debris, giving them a more varied appearance with both dark and light areas.
- Hemorrhagic cysts, which contain blood, might appear with internal echoes or a lacy, reticular pattern.
- Endometriomas (chocolate cysts) often have a ground-glass appearance due to old blood.
- Dermoid cysts can show mixed echogenicity with areas of fat, calcification, or hair.
Size and Location of Cysts
The size of cysts can vary greatly, from a few millimeters to several centimeters, and location is also important, as cysts can be found on the ovaries, in the fallopian tubes, or elsewhere in the pelvic region 1.
Risk Stratification and Management
According to the O-RADS US risk stratification and management system, simple cysts up to 10 cm in diameter are likely to be benign and may be safely monitored using repeat imaging without surgical intervention, even in postmenopausal patients, with follow-up recommendations based on cyst size and patient menopausal status 1.
- For premenopausal patients, no additional management is required for simple cysts less than or equal to 5 cm in diameter, and those less than or equal to 3 cm should be considered physiologic.
- For postmenopausal patients, no further management is suggested in cysts up to 3 cm, and for cysts greater than 3 cm but less than 10 cm, at least 1-year follow-up showing stability or decrease in size is recommended with consideration of annual follow-up for up to 5 years, if stable.
From the Research
Appearance of Vaginal Cysts on Ultrasound
- Vaginal cysts are typically benign, predominantly cystic lesions of the anterior vaginal wall 2
- They can appear as a small lump felt in the vagina or protruding from the vagina, and can be of varying sizes, ranging from the size of a pea to that of an orange 3
- On ultrasound, vaginal cysts can appear as hypoechoic cystic masses 4
- Transvaginal ultrasound or magnetic resonance imaging can be used to diagnose and manage vaginal cysts 5
- Imaging can help to further differentiate the cyst and aid in surgical planning, and can show the location and size of the cyst, as well as its relationship to surrounding structures 6
Characteristics of Vaginal Cysts on Ultrasound
- Vaginal cysts can be fluid-filled and may have a possible connection to the bladder 6
- They can be non-communicating and abut the bladder in its entirety 6
- Ultrasound can help to identify the characteristics of the cyst, such as its size, location, and composition 4
- Magnetic Resonance Imaging (MRI) can be superior to ultrasound in showing multiple cystic lesions of the vagina and their communication with the surrounding structures 4