What to expect from sentinel lymph node biopsy for breast cancer

Before surgery, a tracer is placed near the breast tumour or surgical area. It travels through lymph channels to the sentinel nodes. A surgeon uses the tracer, sometimes with a blue dye, to locate these nodes and removes them through a small incision. The tissue is sent to a laboratory. The result helps the team understand whether cancer cells have reached the nearby lymphatic system and whether further treatment planning is needed.

The biopsy is often performed during breast surgery under anaesthesia. Your breast may feel sore, tight or bruised afterwards, and the incision may be covered with a dressing. Removing sentinel nodes is different from removing many underarm nodes, so ask how the planned operation may affect movement and swelling.

Follow the fasting, medicine and arrival instructions from the surgical team. Tell them about blood-thinning medicines, allergies, pregnancy possibility and any previous reaction to dyes or anaesthesia. Arrange transport home if sedation or general anaesthesia is planned.

At home, keep the wound clean and follow dressing instructions. Use pain relief only as advised, and gradually return to arm movement rather than forcing a stretch. Keep follow-up appointments so the wound and pathology result can be discussed. A temporary change in urine colour can occur after some dyes; ask what your team expects.

Contact the surgical team promptly for increasing redness, warmth, swelling, drainage, wound separation, fever or pain that is worsening rather than settling. Seek urgent help for heavy bleeding, trouble breathing, facial swelling or sudden severe weakness. New or persistent swelling of the breast, arm or hand also deserves assessment, because lymphatic drainage can be affected after node surgery.

Ask which tracer and anaesthetic will be used, how many nodes may be removed, when the pathology result should be available, how to care for the incision, and which arm exercises are appropriate. Ask what the next treatment discussion would involve if sentinel nodes contain cancer cells or if they do not.