A pelvic mass is an abnormal growth or swelling located within the lower abdomen or pelvis. This general term describes any enlargement originating from organs like the ovaries, uterus, bladder, or bowel. Pelvic masses are common, particularly in women, and they span a wide spectrum from fluid-filled sacs that are harmless to more complex tissue growths. Because the term is broad, medical imaging is necessary to determine the mass’s specific appearance, origin, and nature. Many growths, such as small ovarian cysts, are discovered incidentally during routine examinations.
External Signs and Symptoms of a Pelvic Mass
The symptoms a patient experiences often depend on the size of the mass and its exact location, particularly which adjacent structures it presses against. Smaller masses frequently cause no noticeable symptoms, meaning they can remain undetected for a long time. When symptoms do occur, a common complaint is pain or a persistent feeling of pressure and fullness in the lower abdomen.
If the mass is large enough, it may cause visible changes, such as a noticeable bulge or swelling in the abdominal area. The expanding tissue can interfere with the function of nearby organs, leading to changes in bladder and bowel habits, such as a frequent or urgent need to urinate, or difficulty with bowel movements like constipation.
The growth may also cause abnormalities in the menstrual cycle, including unusually heavy or irregular bleeding between periods. A decrease in appetite or feeling full quickly after eating can also be a sign if the mass is pressing on the stomach or intestines.
Visualizing Masses with Diagnostic Tools
Ultrasound is typically the first imaging method used because it is readily available, non-invasive, and effective for initial characterization. This technique uses high-frequency sound waves that bounce off internal structures to create a real-time image. Ultrasound is particularly adept at differentiating between a mass that is primarily fluid-filled and one that is solid tissue.
For masses that remain indeterminate after the initial scan, Magnetic Resonance Imaging (MRI) is often utilized. MRI employs strong magnets and radio waves to generate highly detailed cross-sectional images, providing superior contrast of soft tissues. The high resolution of MRI allows physicians to accurately identify specific tissue components within a mass, such as fat, blood products from hemorrhage, or dense collagen. This level of detail is valuable for determining the mass’s origin and local extent.
Computed Tomography (CT) scans provide rapid cross-sectional views of the entire abdomen and pelvis. CT scans are frequently used in acute situations or for the staging of masses suspected to be malignant, as they effectively detect spread to distant organs or lymph nodes. A combination of these modalities is often employed to build a comprehensive picture.
Key Characteristics Defining Mass Appearance
Physicians use a precise set of descriptive terms to characterize the mass’s physical appearance and internal structure. The most fundamental description is the mass’s composition, categorized as either cystic or solid. A cystic mass appears as a simple, fluid-filled sac with a thin wall.
In contrast, a solid mass is composed primarily of tissue and contains little fluid, which generally raises more concern. Masses may also be described as complex, meaning they contain a mix of both fluid and solid components, often with internal dividing walls known as septations. The complexity increases with the presence of thick septa or solid growths projecting into the fluid space, sometimes called papillary projections.
Another important feature is the mass’s border, which helps indicate its growth pattern. A mass with smooth, well-defined margins often suggests a slow-growing, contained, and benign process. However, borders described as irregular or ill-defined suggest a more aggressive growth pattern and are considered a feature of higher suspicion.
Vascularity, or the blood flow within the mass, is assessed using Doppler ultrasound technology. Strong blood flow within the solid portions of the mass increases the level of clinical concern. Specific measurements, such as a wall or septal thickness exceeding three millimeters, are also important visual characteristics that help distinguish between benign and more serious growths.