Skip to main navigation Skip to main content Skip to footer For Medicare For Providers For Brokers For Employers Español For Individuals & Families: For Individuals & Families Medical Dental Other Supplemental Explore coverage through work How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics Shop for Medicare plans Member Guide Find a Doctor Log in to myCigna
Home Knowledge Center Wellness Library Sentinel Lymph Node Biopsy

Sentinel Lymph Node Biopsy

Test Overview

A sentinel lymph node biopsy is a surgery that takes out lymph node tissue to look for cancer. A sentinel node biopsy is used to see if a known cancer has spread from the original cancer site. A sentinel node biopsy may be done instead of a more extensive surgery called lymph node dissection. But if cancer is found in the sentinel lymph node at the time of surgery, more surgery may be needed to remove additional lymph nodes.

The sentinel lymph node is the first node in a group of nodes in the body where cancer cells may move to after they have left the original cancer site and started to spread. For example, the sentinel node (SN) for breast cancer is normally one of the lymph nodes under the arm.

Your doctor injects a blue dye or special tracer substance or both into the area around the original cancer site. The dye or tracer moves to the first lymph node (sentinel node) that drains close to the cancer site. The dye or tracer makes a map pattern of lymphatic fluid. The map can show where the cancer is likely to spread and which lymph node is most likely to have cancer cells. Your doctor can see the dye or tracer with a special device. The lymph node can be taken out, cut into very thin slices, and looked at under a microscope at the time of surgery. If a sentinel node is positive for cancer cells, more surgery may be needed to remove more lymph nodes.

Other tests, such as a culture, genetic tests, or immunological tests, may be done on the lymph node sample.

Why It Is Done

Why It Is Done

A sentinel lymph node biopsy is done to:

  • See if a known cancer, such as breast cancer or melanoma, has spread to the lymph nodes.
  • Remove a few lymph nodes instead of removing all the lymph nodes in an area. If the sentinel lymph node does not have cancer, this surgery takes less time, is simpler to do, and has a lower chance of long-term problems, such as ongoing swelling of an arm or leg (lymphedema).
How To Prepare

How To Prepare

  • Follow the instructions exactly about when to stop eating and drinking. If you don't, your test may be canceled. If your doctor told you to take your medicines on the day of the test, take them with only a sip of water.
  • Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.
  • Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your test. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it.
  • If you take aspirin or some other blood thinner, ask your doctor if you should stop taking it before your test. Make sure that you understand exactly what your doctor wants you to do. These medicines increase the risk of bleeding.
How It Is Done

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.

Before a sentinel node biopsy is done, a dye, a tracer, or both are injected into the area. The dye stains the sentinel lymph node or nodes so they can be easily seen. The dye may turn your skin blue for a few days after the biopsy. The tracer travels to the sentinel lymph node where it can be detected.

You will be given anesthesia to make you sleep. Or the anesthesia may just numb the area being worked on. The lymph node or nodes are removed. You will have some stitches and a bandage over the biopsy site. The lymph nodes will be looked at under a microscope for cancer.

You will be watched by a nurse in the recovery room until you are fully awake.

How long the test takes

  • The biopsy usually takes 30 to 60 minutes. It may take longer if you have surgery to remove the cancer at the same time.
How It Feels

How It Feels

You will feel only a quick sting from the needle if you have a local anesthesia to numb the biopsy area. If you have a core needle biopsy, you may feel some pressure when the biopsy needle is put in.

You may have general anesthesia if your lymph node biopsy is part of a larger surgery. If so, you won't feel your biopsy at all.

Risks

Risks

It is possible to have some problems after a biopsy. Your doctor will give you instructions on what to do if a problem occurs. Risks include:

  • Bleeding from the biopsy site. This risk is higher for people who have bleeding problems or who take blood-thinning medicines. If you are at risk for bleeding, you may be given blood clotting factors before the biopsy.
  • Skin numbness at the biopsy site.
  • Infection at the biopsy site.
  • Swelling and fluid buildup (lymphedema). This is less likely after a sentinel node biopsy than if more lymph nodes are taken out (dissection).
  • Problems from general anesthesia, if it is used.
  • Damage to nerves at the biopsy site. This may cause weakness or pain.
Results

Results

Test results are usually available within a few days.

The lymph node tissue is usually treated with special dyes (stains) that color the cells so problems can be clearly seen.

Sentinel lymph node biopsy

Normal

The dye or tracer flows evenly to the sentinel lymph node.

The lymph node has normal numbers of lymph node cells.

The structure of the lymph node and the cells look normal.

No cancer is present.

Abnormal

The dye or tracer does not flow evenly to the sentinel lymph node.

The sentinel lymph node cannot be identified.

Cancer cells may be seen. Cancer cells may start in the lymph nodes, such as in Hodgkin lymphoma. Cancer cells may have spread, or metastasized, from other sites, such as in breast cancer or melanoma.

If the sentinel lymph nodes do not have cancer, no other nodes will need to be taken out.

If the nodes contain cancer cells, more nodes may need to be removed.

This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

© 1995-2022 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

Related Links

Medical Tests: Questions to Ask the Doctor

<cipublic-spinner variant="large"><span>Loading…</span></cipublic-spinner>

Page Footer

I want to...

Get an ID card File a claim View my claims and EOBs Check coverage under my plan See prescription drug list Find an in-network doctor, dentist, or facility Find a form Find 1095-B tax form information View the Cigna Glossary Contact Cigna

Audiences

Individuals and Families Medicare Employers Brokers Providers

Secure Member Sites

myCigna member portal Health Care Provider portal Cigna for Employers Client Resource Portal Cigna for Brokers

Cigna Company Information

About Cigna Company Profile Careers Newsroom Investors Suppliers Third Party Administrators International Evernorth

 Cigna. All rights reserved.

Privacy Legal Product Disclosures Cigna Company Names Customer Rights Accessibility Non-Discrimination Notice [PDF] Language Assistance [PDF] Report Fraud Sitemap

Disclaimer

Individual and family medical and dental insurance plans are insured by Cigna Health and Life Insurance Company (CHLIC), Cigna HealthCare of Arizona, Inc., Cigna HealthCare of Illinois, Inc., and Cigna HealthCare of North Carolina, Inc. Group health insurance and health benefit plans are insured or administered by CHLIC, Connecticut General Life Insurance Company (CGLIC), or their affiliates (see a listing of the legal entities  that insure or administer group HMO, dental HMO, and other products or services in your state). Accidental Injury, Critical Illness, and Hospital Care plans or insurance policies are distributed exclusively by or through operating subsidiaries of Cigna Corporation, are administered by Cigna Health and Life Insurance Company, and are insured by either (i) Cigna Health and Life Insurance Company (Bloomfield, CT); (ii) Life Insurance Company of North America (“LINA”) (Philadelphia, PA); or (iii) New York Life Group Insurance Company of NY (“NYLGICNY”) (New York, NY), formerly known as Cigna Life Insurance Company of New York. The Cigna name, logo, and other Cigna marks are owned by Cigna Intellectual Property, Inc. LINA and NYLGICNY are not affiliates of Cigna.

All insurance policies and group benefit plans contain exclusions and limitations. For availability, costs and complete details of coverage, contact a licensed agent or Cigna sales representative. This website is not intended for residents of New Mexico.

Selecting these links will take you away from Cigna.com to another website, which may be a non-Cigna website. Cigna may not control the content or links of non-Cigna websites. Details