The ability to selectively acquire cytological material or histology cores from suspect lesions has revolutionized breast diagnosis.

Any suspicious area that could represent a malignancy should be examined by needle biopsy without undue delay. In this way, we can achieve a prompt diagnosis and alleviate the patients' anxiety immediately. Should a malignant lesion be diagnosed, it can proceed to the appropriate surgery ( and the patient can be informed of her choices before the operation and participate in decision making with the surgeon ). Thus the practice of quick assessment of biopsy material by the pathologist during the operation should be discouraged, as it causes a lot of unnecessary anxiety preoperatively, it carries a risk of false negatives and the woman cannot participate in decision making under anesthesia. Moreover a needle biopsy will often prevent an unnecessary surgery because benign entities like fibroadenomas can be left alone if we have a sample of their benign histology.

In our practice we employ two biopsy techniques:

Fine Needle Aspiration biopsy (FNA) with a 20-23G needle

Fine needle aspiration of a small solid lesion. Cytology reported benign findings consistent with the diagnosis of fibroadenoma.

Fine Needle Aspiration (FNA) is the technique of choice when there is the possibility that the lesion may be a cyst (especially a complex cyst with pseudosolid contents).

Core Needle biopsy of a small solid lesion. Note larger diameter of the special needle (commonly 14 or 16G).

FNA should also be used in the case of an abscess where it is a mistake to disrupt the walls of the abscess with core biopsy.

In these cases our intervention is diagnostic and therapeutic at the same time. Common needles and syringes of the type used for intramuscular injections may be used if the lesion is in a superficial location. Deep-seated lesions may require the use of a longer spinal needle attached to a syringe. The fluid we aspirate is spread on slides and examined by a cytopathologist.

Fine needle aspiration can be used to evacuate cysts and abscesses. The needle is seen inside a 2cm cyst.

The advantages of the FNA technique are simplicity and low cost. It does not require expensive special needles. It can be extremely accurate in trained , skilled hands allowing us to sample even minute 3-4mm lesions. It is possible to investigate multiple lesions in the same session.
The disadvantages of the technique are it yields poor samples, sometimes non-diagnostic from lesions poor in cellularity like hyalinized fibroadenomas and some lobular carcinomas. It is not possible for the cytopathologist to assess the invasiveness of the lesion from cytology slides. If we wish to determine estrogen receptors we have to spread more slides (do more passes)

Core Needle Biopsy

Acquisition of histology samples is possible using special needles attached to a biopsy gun, or a single-use core needle biopsy device.
U pon firing the biopsy gun the special needle (commonly a 14G needle for breast biopsy) is thrust forward a small distance, cutting a core of tissue, that is secured inside the needle. The needle is then removed from the breast, the core removed from the needle and fixed in a 10% solution of formalin and the procedure repeated to obtain the material necessary for diagnosis. Use of a coaxial sheath is recommended to avoid repeated punctures and trauma to the patient. The number of samples depends on the nature of the lesion and on the accuracy of our direction of the needle and of targeting.
The advantages of core needle biopsy are that it allows the acquisition of sufficient material for determination of the nature and character of the lesion by the pathologist in practically every instance. With adequate tissue samples in his hands the pathologist should be able to provide us with a specific diagnosis (which is often not the case with FNA). Histology samples allow the pathologist to determine invasiveness of the lesion, and the presence of estrogen and progesterone receptors. This information is of extreme prognostic significance and will determine our therapeutic options.