A mammogram is a specialized X-ray of the breast, serving as a screening tool for detecting changes within breast tissue. When a mammogram result is “inconclusive,” it means the images are not definitive enough for a radiologist to provide a clear “normal” or “abnormal” diagnosis, requiring further investigation. An inconclusive finding is a common occurrence and does not automatically suggest the presence of cancer.
What Mammogram Results Indicate
Mammogram results are typically categorized to guide healthcare providers on next steps. A “negative” result means no abnormal areas were found, or findings are non-cancerous.
An inconclusive result generally indicates that additional imaging or comparison with previous mammograms is necessary. This classification highlights that while something was observed, its nature is not yet clear, and more information is needed to reach a confident assessment.
Common Causes of Inconclusive Findings
Dense breast tissue is a frequent reason for an inconclusive mammogram. Both dense glandular tissue and potential tumors appear white on a mammogram, making it challenging to distinguish them. About half of women undergoing mammograms have dense breasts, which can obscure abnormalities.
Normal breast tissue can also overlap, creating a suspicious shadow on a two-dimensional mammogram. This “summation shadow” can mimic a mass, requiring further views to confirm it is simply overlapping tissue. Benign findings, such as fluid-filled cysts or tiny calcium deposits known as calcifications, are common and can sometimes resemble more serious issues. Certain patterns or clusters of calcifications may warrant a closer look.
Changes from previous breast surgeries, biopsies, or injuries can create ambiguous areas. Scar tissue or areas of fat necrosis, which is damaged fatty tissue, may appear as densities.
Additionally, technical factors during the mammogram itself, like slight patient movement or imaging artifacts, can result in blurry or unclear images. Inadequate positioning or compression can also affect image quality, requiring repeat views. Hormonal fluctuations throughout the menstrual cycle, during pregnancy, or with hormone therapy can alter breast density and tissue appearance, making interpretation complex.
Follow-Up Procedures
When a mammogram is inconclusive, additional imaging tests are recommended. A diagnostic mammogram is often the first step, involving more focused or magnified views. These specialized images allow radiologists to examine the area more closely than a standard screening mammogram.
Breast ultrasound is another common follow-up, using sound waves to create images. Ultrasound is particularly useful for distinguishing between solid masses and fluid-filled cysts, which often appear similar on a mammogram. In some cases, a breast MRI (Magnetic Resonance Imaging) may be recommended, especially for women with very dense breasts or a higher risk. MRI provides detailed cross-sectional images of the breast, offering a different perspective that can help resolve ambiguous findings.
If, after these additional imaging tests, the finding remains unclear or appears suspicious, a breast biopsy may be recommended. During a biopsy, a small tissue sample is removed from the breast and examined under a microscope by a pathologist to determine if cancer cells are present. Most biopsies performed after an inconclusive mammogram reveal benign, non-cancerous conditions.
Interpreting Your Inconclusive Result
An inconclusive mammogram result can cause concern, but such findings are common and rarely lead to a cancer diagnosis. Approximately 10% of screening mammograms are initially inconclusive, and only about 5% of these ultimately turn out to be cancer. This means the vast majority of women called back for further imaging will find their results are benign.
An inconclusive result indicates the diligence of the screening process, ensuring potential concerns are thoroughly investigated. Promptly attending all recommended follow-up appointments is important to clarify the initial finding and move forward with an accurate diagnosis. Open communication with your healthcare provider can help provide clarity throughout this diagnostic process.