I have a positive mammogram. Do I need a biopsy?

When your doctor tells you that your mammogram is “positive” or “abnormal,” negative emotions and thoughts may flood your mind. Yet, take a step back, know your mammogram score and become empowered to know the next steps. Let’s find out more about when you might need a biopsy.

Mammogram results are expressed in terms of a BIRADS (Breast Imaging Reporting and Data System) scores. A BIRADS score of 1 is considered normal and without any abnormalities. A BIRADS score of 2 or 3 may have an “abnormality” that usually is harmless. Otherwise, mammograms with BIRADS scores of 4 or 5 require further investigation with a biopsy. This is why it is important to know your BIRADS score. The words “positive” or “negative” is not enough. With breast cancer screening we have to be specific. To find out more about BIRADS scores, you can read our blog at Know Your Score .

Depending the BIRADS score, an “abnormal” or “positive” result can lead to another mammogram months later or a biopsy. If your doctor tells you that your BIRADS score is 2 or 3, a repeat mammogram in 1-2 years or a more extensive mammogram with an ultrasound respectively is required. A mammogram with a BIRADS score of 4 and 5 has a considerable chance of being cancerous. Therefore, a biopsy is required in this case. There are 3 major type of biopsies, each with their own advantages and disadvantages.

A biopsy is a surgical procedure where a sample of tissue is taken for further analysis. There are several different biopsy types that can be performed. Notwithstanding, for the purposes of breast cancer, a fine needle aspiration (FNA) and core needle biopsy (CNB) are most common. A fine needle aspiration is performed with a thin needle and can be used if biopsy results are needed immediately while in the operating room. Unfortunately, the results of a fine needle aspiration can be negative when in actuality a mass will ultimately show cancer. This is called a false negative result. A fine needle aspiration may be appropriate for draining a cyst. Yet when cancer is suspected, typically a core needle biopsy is performed.

A core needle biopsy is more precise that a fine needle aspiration and is performed with a thicker needle to obtain a larger sample. A core needle biopsy is also usually performed with an ultrasound, x-ray or MRI to help guide the needle to the correct location within the breast. While a fine needle aspiration is better tolerated and less painful than a core needle biopsy, the results of a core needle biopsy can give more definitive and helpful information. As a result, most breast biopsies are performed with a core needle.

A surgical excision biopsy is more invasive than either fine needle or core biopsy and attempts to remove the mass completely or partially. A surgical biopsy is usually not performed unless a needle biopsy is not possible or failed to give optimal results. (1) A surgical biopsy should not be confused with a lumpectomy, which is the removal of cancer for the purposes of a cure. Before treatment can be considered, a diagnosis has to be made with a biopsy. We try not to perform the most invasive biopsy first, i.e. surgical biopsy, because a woman may need a lumpectomy, removal of a lump within the breast, or mastectomy, removal of the breast itself, in the future. In this way, we can avoid 2 invasive procedures back to back.

After obtaining a mammogram with a BIRADS score of 4 or 5, a breast biopsy is required. This biopsy can be performed with a fine or core needle, each with their own drawbacks and benefits. In all, results from a breast biopsy are typically not needed immediately and the discomfort associated with a core needle biopsy is worth the improved accuracy. Surgical biopsies are not required unless the needle method is not feasible or gives suboptimal results. As always, discuss the best biopsy approach with your doctor as each individual is unique.

REFERENCES
1. Gutwein LG, Ang DN, Liu H, Marshall JK, Hochwald SN, Copeland EM, Grobmyer SR. Utilization of minimally invasive breast biopsy for the evaluation of suspicious breast lesions. Am J Surg. 2011 Aug;202(2):127-32. doi: 10.1016/j.amjsurg.2010.09.005. Epub 2011 Feb 3. PMID: 21295284.