The ultrasound examination is the primary non-invasive method for evaluating the ovaries and identifying potential cysts. This imaging technique uses sound waves to create a real-time picture of the internal pelvic structures. Understanding the specialized medical terminology used in the findings helps translate the radiologist’s report. This knowledge can offer reassurance or clarify why a cyst may require closer follow-up.
Deciphering Ultrasound Terminology
Radiologists use specific terms to describe how tissues reflect sound waves, which determines the colors appearing on the grayscale image. Anechoic describes areas that do not reflect sound waves, appearing completely black, characteristic of simple fluid-filled structures. The terms hypoechoic and hyperechoic describe tissue density by comparing it to surrounding structures. Hypoechoic areas appear darker gray, reflecting fewer sound waves, while hyperechoic areas are brighter gray or white, reflecting many sound waves and often indicating denser or solid material.
A solid component is a tissue-filled structure within the cyst that generates internal echoes, appearing in various shades of gray or white. Septations are thin internal walls or dividers that create multiple compartments within the larger structure. Doppler Flow is an ultrasound technique that adds color (typically red or blue) to show blood flow, used to assess the vascularity of the cyst walls or any solid components.
The Appearance of Simple Cysts
A simple ovarian cyst is the most common finding, typically representing a temporary, functional structure related to the menstrual cycle. These cysts are well-defined, round or oval, with smooth, thin walls. The interior is entirely anechoic (completely black), confirming the presence of clear, simple fluid with no internal echoes or debris.
Because the fluid does not absorb sound waves, the tissue immediately behind the cyst often appears brighter than the surrounding area, a phenomenon called posterior acoustic enhancement. This appearance implies a benign, fluid-filled sac, such as a follicular cyst. Simple cysts usually lack internal blood flow, which is confirmed when Color Doppler is applied.
Simple cysts are often unilocular, meaning they are a single compartment without internal divisions or septations. In premenopausal women, simple cysts measuring up to seven centimeters are almost certainly benign and are frequently followed with observation rather than intervention. The classic simple appearance suggests a low likelihood of malignancy, and these findings are often described as inconsequential.
Key Visual Indicators of Complex Cysts
A cyst is classified as complex when it deviates from the simple, anechoic, thin-walled appearance, incorporating features that require closer evaluation. Complex cysts are defined by the presence of internal structures, such as thick septations or solid components. Septations are internal walls dividing the cyst into multiple compartments; if they are irregular or thicker than three millimeters, they become a significant indicator.
Mural nodules are solid bumps or projections protruding from the inner wall into the fluid-filled space. These solid components are areas of tissue that are not anechoic and can appear hypoechoic or hyperechoic, depending on density. When a solid component is present, the radiologist uses Color Doppler to assess vascularity, or blood flow, within that tissue.
Significant blood flow within the solid parts of a complex cyst is a feature that raises concern, as new blood vessel growth is associated with atypical findings. However, the absence of Doppler flow in a solid nodule is often an encouraging sign. The overall size of the mass, along with the thickness and irregularity of the walls, contributes to the complexity rating and determines the recommended follow-up.
Distinctive Markers of Specific Diagnoses
While many complex cysts are benign, certain specific diagnoses have unique visual markers allowing for confident identification on ultrasound. Endometriomas, often called “chocolate cysts,” are filled with old, thickened blood and typically present as a unilocular mass with homogeneous, low-level internal echoes. This texture is commonly referred to as the “ground glass” appearance due to its uniform, cloudy look.
Dermoid cysts (mature cystic teratomas) are highly recognizable due to their content of hair, fat, and sebaceous material. Their appearance varies, but they often contain highly echogenic (bright) areas that cause acoustic shadowing because the dense material blocks sound waves. A classic marker is the “Rokitansky nodule,” a solid, bright protuberance within the cyst, sometimes causing the “tip of the iceberg” sign.
Hemorrhagic cysts form when a functional cyst bleeds internally, and their appearance changes as the blood clots and dissolves. In the acute phase, they may contain a complex pattern of fine, intersecting lines known as a reticular pattern, sometimes described as a “fishnet” or “cobweb” appearance. A clot may appear as a solid-looking area, but it typically lacks internal blood flow on Doppler and may have concave margins, distinguishing it from a true solid nodule.