A cyst is a sac-like pocket that can form anywhere in the body, filled with fluid, air, or semi-solid material. While finding a new lump can cause concern, the vast majority of cysts are benign and non-cancerous. However, because some cancers can present as a cystic mass, a medical professional must definitively evaluate any suspicious or changing growth. Only diagnostic methods can confirm whether a cyst harbors malignant cells.
Common Types of Cysts
Many people experience a non-cancerous cyst at some point. One frequently encountered type is the epidermal cyst, which forms just beneath the skin. These growths are typically filled with keratin and arise from a blocked hair follicle or gland, commonly appearing on the face, neck, or back. They are almost always benign and grow slowly over time.
Another common type is the ganglion cyst, a non-cancerous lump that usually develops near joints or tendons, most often in the wrist or hand. These are filled with a thick, jelly-like fluid and are thought to result from joint irritation. Functional ovarian cysts are also common in people who menstruate, forming as a normal part of the menstrual cycle. These cysts are overwhelmingly benign, generally asymptomatic, and tend to resolve on their own within a few cycles.
Self-Observed Indicators of Malignancy
While benign cysts are common, certain observable characteristics should prompt immediate evaluation, as they may suggest a mass is potentially malignant. A significant warning sign is rapid or unexplained growth over a short period. Unlike pliable, fluid-filled cysts, a cancerous mass may feel firm, hard, or lumpy.
The mobility of the lump is also important; a typical benign cyst often moves slightly under the skin, while a cancerous growth may be fixed or immobile because it has anchored itself to surrounding deep tissue. Changes to the overlying skin should also be noted, such as discoloration, scaling, ulceration, or dimpling.
The presence of persistent pain or tenderness in a newly formed lump, especially without signs of infection like redness or warmth, warrants medical assessment. Systemic symptoms accompanying a lump are particularly concerning, suggesting a process impacting the entire body. These include:
- Unexplained weight loss.
- Persistent fever.
- Night sweats.
- Bleeding or oozing material without trauma.
Clinical Diagnostic Methods
A medical professional begins the evaluation process with a detailed physical examination and a comprehensive history, noting the cyst’s location, consistency, and associated symptoms. Diagnostic imaging often follows, helping characterize the mass before a biopsy is considered.
Imaging Techniques
Ultrasound is typically the first-line imaging tool because it is non-invasive and effective at differentiating a simple, fluid-filled sac from a solid or complex mass. Simple cysts that appear uniform on ultrasound are almost always benign and may only require watchful waiting. If the mass is deeper or the ultrasound indicates solid components, a computed tomography (CT) scan or magnetic resonance imaging (MRI) may be ordered. These advanced scans provide detailed cross-sectional images that help define the mass’s borders and its relationship to surrounding structures.
Aspiration and Biopsy
In some cases, aspiration is performed, using a fine needle to drain fluid from the lump. If the fluid is clear and the mass collapses, it strongly suggests a benign simple cyst. The definitive method for determining if a mass is cancerous remains the biopsy. This procedure involves removing a tissue sample, either through a fine needle aspiration (FNA) of cells or a core biopsy of a solid portion. The collected tissue is then analyzed by a pathologist to look for abnormal or malignant cells. Blood tests for tumor markers, such as CA125, may also be used alongside imaging to assess malignancy risk, particularly with complex ovarian cysts.
Seeking Professional Evaluation
Any new, growing, or changing lump should be brought to the attention of a healthcare provider without delay. Even if a cyst appears to be a common, benign type, professional examination is the only way to establish an accurate diagnosis and rule out a more serious underlying condition. It can be difficult to distinguish a harmless cyst from a cancerous growth by sight or feel alone.
Seeking prompt medical attention ensures that if a malignancy is present, it can be detected early, which improves treatment outcomes. Regular monitoring of any known benign cysts is also important, as any new pain or change in appearance should trigger a follow-up appointment.