The Integrated Breast Center at Pennsylvania Hospital
About the Center | Programs & Treatments | Supportive Care | Clinical Research | Resources
Programs and Treatments
Bloodless Medicine & Surgery
Cancer Risk Evaluation Program
Geriatric Oncology
GYN Oncology
HIV Oncology Program
Inpatient Oncology
Integrated Breast Center

About Our Team

Oncology Nurse Navigator

Services We Offer

Clinical Research

Resources for Patients
Health Information:

Sentinel Lymph Node Biopsy

Lymphedema Following Breast Surgery

Management of Cancer

Exercises after Surgery
Medical Oncology
Pathology Services
Post-treatment Services
Radiation Oncology
Radiology Services
Sarcoma Program
Second Opinion
Stem Cell Transplant Program
Surgical Oncology
<< Back to ACC at PAH home page

About Sentinel Lymph Node Biopsy

What is the lymph system?
The lymph system is important in your body’s defense against infection. It is made up of lymph vessels and lymph nodes. The lymph vessels collect fluid and protein from surrounding body tissues. This fluid then goes through the lymph nodes, which act to filter out and trap bacteria, viruses, cancer cells, and other unwanted substances. Lymph nodes can be found clustered in various parts of the body, including the neck, axilla (underarm area) and groin.

What is a sentinel lymph node biopsy?
The sentinel lymph node biopsy is an alternative to the axillary lymph node dissection when all of the lymph nodes are removed. The sentinel lymph node is the first node or nodes that are “standing guard” for your breast. If cancer cells are breaking away from the tumor and traveling through the lymph system, the sentinel node(s) are the first lymph nodes to which cancer would spread.

In a sentinel node biopsy for breast cancer, your surgeon looks under the arm (axilla) for the first lymph node(s) that drain the breast. Only those lymph nodes identified as sentinel lymph nodes are removed. If the sentinel node(s) do not have cancer, chances are the other nodes in the axilla have not been affected and can be left alone. If he sentinel lymph node biopsy is positive, however, spread to other lymph nodes is possible and a full axillary dissection would be recommended.

How is a sentinel lymph node biopsy performed?
The sentinel node is identified by utilizing a radioactive tracer, a blue dye, or both modalities. If your surgeon utilizes the radioactive tracer, you will go to Nuclear Medicine on the day of surgery where you will receive a small amount of radioactive tracer injected around the tumor or under the nipple. A scan will be done to trace the flow of the radioisotope through the lymph system to find the location of the sentinel node(s). This part of the procedure takes 60-90 minutes.

You will then be taken to the operating room where the surgeon injects a blue dye into the area around the tumor or under the nipple. This is done after you receive general anesthesia. The blue dye flows through the lymphatic system into the sentinel lymph node(s), coloring them blue.

The surgeon has a small device, called a gamma probe that can be used like a Geiger counter to look at the activity of the radioisotope in the various lymph nodes that drain the breast. This probe helps the surgeon find the location of the sentinel lymph node(s).

Through a small incision under the arm, the surgeon identifies any lymph nodes that are blue-stained, radioactive or palpably abnormal, and these nodes are removed. These are sent to the Pathology lab for an immediate reading (frozen section). If the node(s) have tumor in them, an axillary node dissection is performed.

If the sentinel node(s) are clean, no further axillary surgery is performed. There is a 5 percent chance that the sentinel node(s) will be clean on the frozen section, but may contain small amounts of tumor when studied more extensively on the permanent sections. If this happens, you will need to return to the operating room for a completion axillary dissection.

Remember that the radioisotope dye and lymph node scan does not tell you that the cancer has spread. They only mark the first node(s) that the cancer cells might have spread to so that the surgeon can remove them to be tested. Only the pathologist, by looking under the microscope, can tell whether cancer cells have spread to the lymph nodes.

What are the risks of a sentinel lymph node biopsy?
As with any surgery, there is a risk of bleeding, infection and poor wound healing. Fluid or blood could accumulate and require drainage. A small percentage of patients, less than 1 percent, may have an allergic reaction to the blue dye. There will be some blue staining in the breast skin for a few weeks to several months. You will also have blue urine for a few days, which is normal. There is a 2-3 percent chance of getting arm swelling (lymphedema) following a sentinel lymph node biopsy.

How will I look and feel after the sentinel lymph node biopsy?
You will have a small scar under your arm. Initially there will be some swelling and discomfort.

How long will I be in the hospital?
You may be discharged from the Ambulatory Procedure Unit on the same day. Following surgery, you will be in the recovery room until your discharge. You will need to be picked up by a responsible adult at the time of discharge. Please inform family members that this process will take most of the day.


appointment icon

Need an appointment? Request one online 24 hours/day, 7 days/week or call 800-789-PENN (7366) to speak to a referral counselor.

Related Links
Find a Cancer Specialist
Request an Appointment Online or call
800-789-PENN (7366)
Pennsylvania Hospital Visitor Information
Give Now to JKCC
Encyclopedia Articles about Cancer




About Penn Medicine   Contact Us   Site Map   Privacy Statement   Legal Disclaimer   Terms of Use

Penn Medicine, Philadelphia, PA 800-789-PENN © 2015, The Trustees of the University of Pennsylvania space