Core needle biopsy

What does the procedure involve?

Core needle biopsy (CNB) involves removing small strands of tissue from a lump using a needle. The procedure is done through a 2mm hole in the skin under local anaesthetics. The needle is usually guided to the lump using ultrasound. The aim is to take 4-6 pieces of tissue for assessment under the microscope. What kind of results does it give? CNB tells you what the targeted lump is (i.e. histological diagnosis) so that we can discuss the management of the lump.

When should I consider a core biopsy?

CNB is the preferred choice across the world to find out the nature of a lump in the least invasive and least expensive way. In the case of a breast cancer, further tests can be done on the tissue sample to give further information to help plan and tailor the treatment to the individual.

What are the risks?

The risk of CNB include bleeding, bruising, temporary swelling and scarring (including keloid scarring). Because the needle is deployed under direct control with real-time ultrasound, there is a very very small risk of injuring the chest muscles, ribs and lungs. There may be a little bit of discomfort afterwards, which goes away with paracetamol (Panadol). For small lumps (usually <5mm), there is a chance of missing the lump (sampling error). The histology report does not match and further investigations will be needed.

Procedure information

  • Type of Anaesthetic: Local
  • Length of procedure: 20-30 minutes
  • Nights in Hospital: None. Procedure done in clinic
  • Recovery: 24 hours (1 day medical certificate given)