An abnormal finding in a breast ultrasound typically refers to the detection of unusual structures or changes within the breast tissue that warrant further investigation. Often, an ultrasound is performed as a follow-up to an abnormal mammogram, serving to clarify the nature of a suspicious area. Its primary purpose is to determine the consistency of a detected lump—whether it is a fluid-filled cystic lesion or a solid lump. While many abnormalities are benign, some solid lumps could be cancerous, necessitating careful evaluation.
Understanding Abnormalities
Breast ultrasounds use sound waves to create images of the breast's internal structures. Radiologists analyze these images for characteristics that deviate from normal breast tissue, such as:
1. Lumps or Masses
The most common reason for an ultrasound is to investigate a palpable lump or an area of concern seen on a mammogram. Lumps are generally categorized by their consistency:
- Cystic Lesions (Fluid-Filled Lumps): These are sacs filled with fluid and are almost always benign.
- Simple Cysts: These appear as perfectly round or oval, smooth-walled, anechoic (black on ultrasound, indicating fluid) structures with posterior acoustic enhancement. They are typically harmless and do not require further intervention.
- Complicated Cysts: May contain debris or thin septations. While still often benign, they might occasionally require short-term follow-up to ensure stability.
- Complex Cysts: These have thicker walls, internal solid components, or irregular shapes. They carry a higher suspicion and often require biopsy or closer monitoring due to a small risk of malignancy.
- Solid Lumps: These are masses composed of tissue, not fluid. Their appearance on ultrasound helps determine their potential nature.
- Benign Solid Lumps: Examples include fibroadenomas (common, non-cancerous tumors), lipomas (fatty tumors), or hamartomas. These typically have smooth, regular shapes, well-defined margins, and a wider-than-tall orientation.
- Potentially Malignant Solid Lumps: Features that raise suspicion for cancer include:
- Irregular Shape: Not round or oval.
- Spiculated Margins: Jagged, star-like borders indicating invasion into surrounding tissue.
- Taller-than-Wide Orientation: The mass is taller than it is wide on the ultrasound image.
- Posterior Shadowing: The area behind the mass appears dark, indicating that sound waves are being blocked or absorbed.
- Microcalcifications: Tiny calcium deposits within the mass (though ultrasound is less sensitive for these than mammography).
- Increased Vascularity: More blood flow to the area, which can be seen with color Doppler ultrasound.
2. Non-Mass Lesions
Sometimes, an ultrasound might reveal other abnormal findings that are not distinct lumps but represent changes in breast tissue:
- Architectural Distortion: Disruption of the normal tissue pattern, where lines of tissue converge towards a central point without an obvious mass. This can be a subtle sign of malignancy.
- Asymmetric Densities: An area of breast tissue that appears denser than the corresponding area in the other breast, or compared to other parts of the same breast.
- Skin Thickening: Unusual thickening of the skin of the breast, which can be a sign of inflammation or certain types of aggressive cancer (e.g., inflammatory breast cancer).
- Duct Ectasia or Dilation: Widening of the milk ducts, sometimes with fluid or debris. While often benign, it can occasionally be associated with inflammation or, rarely, malignancy.
- Lymphadenopathy: Enlarged or abnormal-looking lymph nodes in the axilla (armpit) or within the breast. While reactive (normal response to infection) nodes are common, suspicious features (e.g., thickened cortex, loss of fatty hilum) may indicate spread of cancer.
How Abnormal Findings are Classified
Radiologists use the Breast Imaging Reporting and Data System (BI-RADS) to categorize breast imaging findings, including those from ultrasound. This system provides a standardized way to describe findings and recommend follow-up.
| BI-RADS Category | Interpretation | Recommended Action |
|---|---|---|
| 0 | Incomplete – Need additional imaging | Additional imaging (e.g., diagnostic mammogram, ultrasound) |
| 1 | Negative | Routine follow-up |
| 2 | Benign (Non-cancerous) | Routine follow-up |
| 3 | Probably Benign – Short-interval follow-up | Follow-up ultrasound in 6 months to confirm stability |
| 4 | Suspicious Abnormality | Biopsy is recommended |
| 5 | Highly Suggestive of Malignancy | Biopsy and definitive treatment recommended |
| 6 | Known Biopsy-Proven Malignancy | Surgical excision or treatment |
Any finding categorized as BI-RADS 3 or higher is considered an abnormal ultrasound result that requires further action, ranging from close monitoring to a biopsy, to accurately determine its nature.
For more information on breast health and screenings, you can visit resources like the American Cancer Society or RadiologyInfo.org.
