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Sentinel Lymph Node Biopsy


A sentinel lymph node biopsy is a surgery that takes out lymph node tissue to look for infection or cancer. Test results from 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

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.


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's lymphoma. Cancer cells may have spread, or metastasized, from other sites, such as in breast cancer or melanoma.

What Affects the Test

It may not be possible to have a clear result from the small sample taken during a sentinel lymph node biopsy. Surgery to remove more lymph nodes (axillary dissection) may be needed.

What To Think About

  • In a sentinel lymph node biopsy, less tissue is taken out but more sections of tissue are looked at than by a standard lymph node dissection. But if cancer is found, additional surgery may be needed to look at more lymph nodes.
  • Swelling in the area around the biopsy site is less common with sentinel lymph node biopsy than with a lymph node dissection.
  • The dye may cause your skin to be blue for several days after the biopsy. It may also cause your urine to turn green for 1 to 2 days.
  • It is possible to have false-negative results from the small sample taken during a sentinel lymph node biopsy.

Other Works Consulted

  • American Cancer Society (2010). Breast Cancer: Treating Breast Cancer. Available online:

  • Cody HS (2010). Axillary dissection. In JR Harris et al., eds., Diseases of the Breast, 4th ed., pp. 562–569. Philadelphia: Lippincott Williams and Wilkins.

  • National Cancer Institute (2011). Sentinel Lymph Node Biopsy. Available online:

  • Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.

ByHealthwise Staff
Primary Medical ReviewerSarah Marshall, MD - Family Medicine
Specialist Medical ReviewerC. Dale Mercer, MD, FRCSC, FACS - General Surgery
Last RevisedFebruary 27, 2012

WebMD Medical Reference from Healthwise

Last Updated: February 27, 2012
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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