Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Breast Cancer Health Center

Select An Article

Breast Cancer and the Sentinel Node Biopsy

Font Size

In breast cancer, a sentinel node biopsy pinpoints the first few lymph nodes into which a tumor drains (called the "sentinel" node). This helps doctors remove only those nodes of the lymphatic system most likely to contain cancer cells. The sentinel nodes are the first place that cancer is likely to spread.

In breast cancer, the sentinel node is usually located in the axillary nodes, under the arm. In a small percentage of cases, the sentinel node is found somewhere else in the lymphatic system of the breast. If the sentinel node is positive, there may be other positive lymph nodes upstream. If it is negative, it is highly likely that all of the upstream nodes are negative.

Recommended Related to Breast Cancer

Girl's Guide to Preventing, Avoiding, Treating, and Even Beating Cancer

By Ashley Ross and Sophie Banay MouraCancer: The word alone can paralyze us. Instead of protecting ourselves, we resort to magical thinking—it won't happen to me. That's a mistake. Rates of the top five cancers in women 20 to 39—in order, they are breast, thyroid, melanoma, cervical, and colorectal—are rising. The good news: There's a lot you can do to prevent them. We talked to the country's top doctors and mined the latest research for Marie Claire's first-ever cancer crash course. Here, how to...

Read the Girl's Guide to Preventing, Avoiding, Treating, and Even Beating Cancer article > >

How is a Sentinel Node Biopsy Performed?

To locate the sentinel nodes, a labeling substance, either a radioactive tracer, blue dye, or both, is injected into the area around the tumor before a mastectomy or lumpectomy is performed. The tracer travels the same path to the lymph nodes that the cancer cells would take, making it possible for the surgeon to determine the one or two nodes most likely to test positive for cancer by either visualizing the color or using a handheld Geiger counter. This method varies in how it is performed among hospitals.

What Are the Advantages of a Sentinel Node Biopsy?

Research suggests that the sentinel node biopsy procedure can be useful in determining which lymph nodes to remove, without the risk of complications associated with surgically removing all potentially cancerous nodes.

When a lumpectomy or mastectomy is performed, only a few lymph nodes are removed for laboratory analysis using the sentinel node biopsy technique. In traditional lumpectomy or mastectomy procedures, a greater number of the axillary nodes are removed, which may lead to complications after surgery, such as lymphedema, or swelling of the arm or hand.

WebMD Medical Reference

Reviewed by Angela Jain on June 19, 2014
Next Article:

Today on WebMD

Breast Cancer Overview
From self-exams and biopsies to reconstruction, we’ve got you covered.
Dealing with breast cancer
Get answers to your questions.
woman having mammogram
Experts don’t agree on all fronts, but you can be your own advocate.
woman undergoing breast cancer test
Many women worry. But the truth? Most abnormalities aren’t breast cancer.
Breast Cancer Treatments Improving
Resolved To Quit Smoking
Woman getting mammogram
Screening Tests for Women
ovarian cancer overview slideshow
serious woman
what is your cancer risk
10 Ways to Revitalize Slideshow