What should you know about sentinel needle biopsy?

The sentinel node is chosen because lymph fluid from a tumour area reaches it early. Imaging or a tracer may help the clinician locate it, and local anaesthetic is commonly used for a needle sample. A pathologist examines the tissue and may use immunohistochemistry to look for specific markers.

Needle sampling can provide useful information without removing the entire node, although the team may recommend another procedure if the sample is too small or does not answer the clinical question. Results are interpreted with the original tumour findings and imaging.

Tell the clinic about blood-thinning medicines, bleeding conditions, allergies, pregnancy, and difficulty lying in the required position. Follow instructions about eating, drinking, and medicines. Wear clothing that gives easy access to the sampling area. Afterward, keep pressure on the site as advised and avoid heavy lifting until the team says it is suitable.

Ask how the result will be delivered and whether a larger biopsy or another scan could be needed. Background information is available in Biopsy.

Get advice if bleeding does not stop with firm pressure, or if the puncture site becomes increasingly painful, red, warm, swollen, or wet. Seek urgent help for difficulty breathing, facial swelling, faintness, or a rapidly spreading rash. Tell the team about new weakness, severe pain, or swelling that persists beyond the expected recovery period.

Ask whether the sample will be guided by ultrasound or another method, how much tissue is needed, and when you can bathe or exercise. Find out what an adequate, inconclusive, or cancer-positive result could mean for MRI, genomic tumour profiling, or treatment planning.