Procedures: When is A Breast Biopsy Needed?
What It Is:
A breast biopsy means obtaining tissue samples for analysis, to determine the nature of the breast abnormality of concern. In other words, it means taking samples from the breast to check for cancer.
Breast cancer is the most common cancer among women in Singapore. If a significant abnormality is seen on mammogram and ultrasound, a biopsy may be considered to check if it is due to cancerous changes.  If a woman has symptoms such as a breast lump that she or her doctor can feel, or abnormal nipple discharge, then a biopsy may also be required.
Not every abnormality detected on mammogram or ultrasound requires a biopsy. Some findings are due to hormone effects on the breast tissue and are benign (non cancerous), so a biopsy is not needed. Other findings however may be suspicious requiring a biopsy for confirmation.
Mammogram calcifications or microcalcifications
These are tiny calcium deposits in the breast tissue that are visible on the mammogram. These may be normal or due to hormone changes, but sometimes they are an indication of early cancer change in the breasts.
Descriptions such as rim, rounded, punctuate, scattered and macrocalcifications on your mammogram report suggest that the calcifications are due to non cancerous causes. So a biopsy is usually not necessary. However, terms such as cluster, pleomorphic, segmental and granular may suggest a risk of malignancy, and your doctor may discuss with you the level of risk and recommend a biopsy.
Cysts
Cysts by definition are collections of fluid lined by breast cells. They appear because of hyperactive breast cells that secrete fluid which then collects to form a cyst. Cysts may be as tiny as 2-3 millimetres, or may be as large as 2-3 centimetres.
Cysts are mostly benign although occasionally cancerous cysts are encountered. Cancerous cysts are usually fairly large and will often have atypical appearances on ultrasound such as presence of mural nodule, cluster, wall calcifications etc. If these features are present, the cyst should be closely monitored or biopsied.
Large non-cancerous cysts may cause pain due to tension in the cyst. This is resolved by a simple fine needle aspiration of the cyst fluid.
Solid nodules or lumps
Solid nodules or lumps in the breasts may due to hormone changes such as fibrocystic change, or may be due to a tumour. Tumours or growths can be cancerous or non cancerous. If the lump is of a significant size or has indeterminate features such as shadowing, microlobulations, irregular margin, tall-than-wide, increased blood flow or if it is associated with enlarged lymph nodes, then a biopsy is highly recommended as the risk of the lump being cancer is significant.
Breast biopsies
There are many types of breast biopsies, depending on the type of abnormality seen, size of abnormality and risk of cancer. These include fine needle aspiration cytology, core needle (tru-cut) biopsy, vacuum assisted biopsy (mammotome) or open surgical biopsy.
  • Fine needle aspiration cytology – this uses a small needle to obtain material from the abnormal area for examination of the cells. It takes only a minute or two to perform and is done in the clinic. There are no risks but occasionally the result can be equivocal or indeterminate necessitating further tests.
  • Core needle biopsy – this uses a special needle to obtain cores of tissue from the abnormal area of the breast. It is done under local anaesthesia and may take 15-30 minutes. This usually gives a definitive diagnosis as a good amount of tissue is extracted for histological examination.
  • Vacuum assisted biopsy (mammotome) – this can be done under mammogram guidance or ultrasound guidance depending on the type of abnormality in the breast. It is a specially designed minimally invasive device for breast biopsies. Because there is a vacuum function, a larger amount of tissue can be removed, so if the lump or abnormal area is relatively small, the entire abnormality can be removed for examination so it gives very high accuracy. This is also usually performed under local anaesthesia.
  • Open surgical biopsy – this is done if the abnormality is relatively large or if the needle biopsy is technically not possible. This is usually done under general anaesthesia, and in most cases the entire abnormality will be removed for analysis unless it is too extensive.
Breast cancer is the most common cancer among women in Singapore but it can be effectively treated if detected in the early stages.   The majority of findings on screening mammogram or ultrasound will be benign so do not be alarmed.  However, if you have significant symptoms or if there are significant findings or changes on imaging tests, do have a discussion with your doctor to see if a breast biopsy is required.
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Index of Published Articles
Q & A: Nipple Itch
Breast Cancer in Today's World: fortunately treatment is getting better and less invasive
When is A Breast Biopsy Needed?