Breast sampling methods
Aspiration only used for breast cysts
Fine needle aspiration (FNA) can be used for lymph nodes to determine whether the breast cancer cells have spread to the lymph nodes. But no cellular archiecture is preserved and it also cannot tell you anything about the subtype of cancer and whether it is estrogen, progesterone or HER2 positive.
Core biopsy is the most common and preferred method of biopsy as it gives the most information and is not as invasive as an excisional biopsy. It is typically done under imaging guidance such as mammography (stereotactic), ultrasound or MRI.
Excisional biopsy is only used if pathology from core biopsy is uncertain. It is an open surgical procedure that should only be performed if core biopsy could not be performed.
Skin biopsy (punch biopsy typically) is usually only done if you suspect there is skin involvement as seen in Paget’s disease of the nipple or breast (DCIS cells spread into lactiferous sinuses and the overlying skin of the nipple resulting in excoriations, crusting and ulceration of the areola and nipple) and inflammatory breast cancer (cancer spread to lymphatics of breast and overlying skin resulting in red, hot angry inflamed breast).
DCIS (ductal carcinoma in situ) is a precursor to invasive ductal carinoma. LCIS (lobular carcinoma in situ) is not a specific precursor but it does increase the risk of breast cancer in either breast.
Image guided biopsy
- Stereotactic biopsy
- Process
- Lie face down on exam table, with breast sticking out of opening in table OR seated position
- The affected breast will be compressed between two plates to help with identifying the location of the lesion in question in order to plan the insertion of the biopsy needle
- Mammogram is best for detecting calcifications
- Preferred method when there are macrocalcifications present
- Process
- Ultrasound guided biopsy
- Process
- Lie facing up on exam table
- Radiologist will simply use ultrasound transducer as they normally would with no special positioning or compression plates required
- Using ultrasound they can identify the location of the lesion in question, and insert the biopsy needle into the mass
- Preferred method
- Better tolerated by patients
- Typically used if a mass is detected on imaging
- Process
- MRI guided biopsy
- Process
- Lie face down on exam table, with breast sticking out of opening in table
- The affected breast will be compressed between two plates to help with identifying the location of the lesion in question in order to plan the insertion of the biopsy needle
- Not widely available
- Only required if lesion is only found on MRI and not on ultrasound or mammogram
- Process
Localizing lesions to be found in the OR
- If mass is not palpable, you need a way to localize the lesion in the OR
- 2 methods
- Radioactive seed
- Small titanium seed that emits a radioactive signal and then a probe in the OR is used to identify the location of the seed
- Preferred and more comfortable for patients
- Wire
- Radioactive seed