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Breast Cancer Health Center

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Sentinel Lymph Node Biopsy

How To Prepare

Tell your doctor if you:

Follow your doctor's instructions carefully. If you are given a medicine (sedative) to make you relax or sleep before the biopsy, do not eat or drink for 8 hours before the biopsy. Arrange for someone to drive you home after the biopsy.

Talk to your doctor about concerns you have regarding the need for the test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).

How It Is Done

You will need to take off clothing near the biopsy site. You will wear a gown for a covering during the test.

If you are very anxious about the biopsy, you may be given a medicine (sedative) to help you relax.

Before a sentinel node biopsy is done, the dye or tracer is injected into the area, and a special camera (lymphoscintigraphy) takes pictures of the lymph nodes. Some doctors use pain medicine with the dye to reduce discomfort. The dye may turn your skin blue for a few days after the biopsy.

The first lymph node or nodes to absorb the tracer are called the sentinel nodes. This node or nodes and the tissue around them are taken out. You may have a numbing medicine (local anesthesia) or go to sleep for the biopsy. The lymph node sample is cut into many thin slices and looked at under a microscope for cancer. You will have some stitches and a bandage over the biopsy site.

A sentinel lymph node biopsy usually takes 30 to 60 minutes but may take longer. If you have general anesthesia, you will be watched by a nurse in the recovery room until you are fully awake.

Your doctor will give you specific instructions to take care of your biopsy site. During your follow-up visit, your doctor will discuss the results of your biopsy with you and take out your stitches.

WebMD Medical Reference from Healthwise

Last Updated: November 14, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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