Breast tissue sampling - Investigations/procedures

Breast tissue sampling

Needle core biopsy and fine needle aspiration are both effective methods for taking tissue samples from breasts, but as needle core biopsy is more likely to give an unequivocal result and inadequate sampling is less common, most centres in the United Kingdom now perform needle core biopsy. However, needle core biopsy false negative rates are higher than fine needle aspiration and fine needle aspiration allows aspiration of cystic lesions. Fine needle aspiration may also provide cytology results on the same day (one stop clinic) helping to alleviate anxiety at a particularly stressful time for the patient.

Fine needle aspiration: The lesion is fixed between the index finger and thumb and a fine needle attached to a syringe (often in a holder) is inserted into the lesion through the stretched skin and subcutaneous tissue. Aspiration is performed by exerting gentle negative pressure through the syringe. A number of passes are made through the lesion at differing angles whilst negative pressure is maintained.

Needle core biopsy: Local anaesthetic is infiltrated into the area. A small skin incision is made to allow insertion of the core biopsy needle. Under ultrasound guidance the needle is advanced to the edge of the lesion and the biopsy gun is fired. Ultrasound is used to confirm that the needle passes through the lesion. One or two passes are usually sufficient to obtain diagnostic material.

Cytology from either procedure is graded into five categories (see Table 10.3).