Types of biopsies of the breast
Fine needle aspiration cytology (FNAC)A fine needle attached to a syringe is used to withdraw cells from the suspicious area(s) and then examined under a microscope. If the lump is large enough for the doctor to feel, the needle can be guided easily. If it is not possible to locate the tumour easily, then an ultrasound is used to guide the needle toward the suspicious lump. This is called an ultrasound-guided FNAC. The advantage is that it does not require any form of anaesthesia. The disadvantage is that it cannot differentiate between cancer and pre-cancer, cannot differentiate between certain types of benign / noncancerous lumps and does not yield tissue adequate for sensitivity testing. If the report is not definitive, a second type of biopsy may be done.
Core needle biopsy A larger, hollow needle is used to withdraw small cylinders of the tissue from the abnormal area of the breast and is done under a local anaesthetic. The needle is inserted 3-6 times to get multiple samples from different locations of the suspicious area. This type of biopsy gives a clearer picture and takes more time to report, as several samples taken are to be checked. The core needle biopsy does not leave scars but may cause some bruising. An ultrasound or mammogram may be used to guide the needle to the exact location if not felt well clinically. This yields accurate diagnosis in almost 95% of the cases and is hence the biopsy method of choice.
Surgical (open) biopsy is of two types:
- Incisional biopsy: Only a small portion of the suspicious area is removed to enable a diagnosis.
- Excisional biopsy: The entire lump or suspicious area is removed taking care not to remove any breast tissue.
A surgical biopsy is done by making an incision and putting stitches; may leave a scar. It is done for diagnostic purposes if there is any ambiguity even after doing a core biopsy.