Biopsy

Performed as an outpatient procedure, fine-needle aspiration biopsy may be used to:

• distinguish cysts from solid lumps
• obtain cells for cytology

The main problem with the technique is the rate of:

• false positives; 1-3% of all cases and mainly due to:
  • hypercellular fibroma cells interpreted as malignant
  • effect of hormones on breast:
    • HRT
    • pregnancy
    • lactation
• false negatives; 10-20% of all aspirates; mainly due to:
  • aspiration track does not encounter malignant cells
  • some forms of carcinoma are particularly acellular

If fine needle aspiration fails or is negative a core-needle biopsy may be performed. If core needle biopsy is negative, an open biopsy can be undertaken. In some situations, surgeons may choose to proceed directly from fine-needle aspiration to open biopsy. Frozen section histology of the lump intra-operatively may dictate the extent of excision performed.