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Sentinel lymph node biopsy

A procedure to determine whether your breast cancer has spread to your lymph nodes

Close up of a Sentinel lymph node biopsy scar
The lymphatic system is part of the body's immune system. It is made up of lymph nodes, and a network of vessels that carry fluid called lymph around the body. Lymph contains white blood cells that fight infection and carries waste products and fluid from our cells and tissues.

The lymphatic system is one of the most common ways that cancer spreads through the body, and one of the best ways to see if your cancer has spread is to check the lymph nodes to see if they contain cancer cells.

Sentinel means 'guard' and cancer normally spreads to the sentinel lymph nodes first. If you have been diagnosed with breast cancer, a sentinel lymph node biopsy is a procedure where one or more sentinel lymph nodes are removed and checked for cancer cells. These nodes are usually located in the axilla (armpit). A sentinel lymph node biopsy may be done on its own, or at the same time as surgery to remove a breast lump called a lumpectomy.

Call or book online today to arrange a consultation to discuss a private sentinel lymph node biopsy with a consultant of your choice at Circle Health Group.

This page explains what a sentinel lymph node biopsy is, how the procedure is carried out and what to expect during your surgery and recovery.

A sentinel lymph node biopsy helps your consultant to stage your cancer by determining how much your cancer has spread. This allows your consultant to decide whether you need further investigations and plan the most appropriate treatment. If your sentinel node biopsy is negative, it may be possible to prevent more extensive lymph node surgery which can cause problems with lymph drainage and lead to complications such as swelling and lymphoedema.

At your first consultation, you will typically be seen by a consultant breast surgeon, a specialist in breast surgery and care. Your consultant will ask you about your symptoms and medical history. They may perform a physical examination and ask to see any previous tests or scans you have had.

At Circle Health Group, your first appointment is important as it's where we get to know you, discuss your diagnosis, and encourage you to ask any questions you may have.

At the end of your appointment, your consultant will decide if a sentinel lymph node biopsy is a suitable procedure for you based on your diagnosis, general health and the results of your previous tests and scans. They will explain the procedure to you including what happens during the surgery, any possible risks and complications, and what to expect afterwards.

It is important to us that you are as well-informed and comfortable as possible during your time with us, so please ask your consultant any questions you may have.

There is normally little to no preparation involved before having a sentinel lymph node biopsy. Any instructions will be in your appointment letter. Please follow any instructions carefully and call the hospital if you have any questions or concerns.

Before your biopsy, tell your consultant about any medications you are taking including supplements and over-the-counter medicines. Your consultant may tell you to stop taking some medications such as blood thinners for a few days before your procedure. This is to reduce the risk of bleeding.

On the morning of your sentinel lymph node biopsy, take a bath or shower. Don't shave your armpit yourself or apply lotion, deodorant, jewellery, or nail polish.

A sentinel lymph node biopsy is carried out under general anaesthetic, which means you'll be asleep during the procedure.

Before your procedure, you will be given an injection into your breast containing a small amount of a safe radioactive substance. Once the anaesthetic has taken effect, your consultant will inject a blue dye around your nipple area. In combination with the radioactive substance, this allows your consultant to locate your sentinel lymph nodes.

Next, your consultant will make a small incision in your armpit and remove one or more of your sentinel lymph nodes. Normally between one and five lymph nodes are removed during the procedure. Your consultant will close the incision with surgical glue, tape, or stitches.

The removed sentinel nodes will be sent to the laboratory to check for cancer cells.

Sentinel lymph node biopsy normally takes around 45 minutes. If you are having a lumpectomy at the same time, the procedure will take approximately ninety minutes.

Recovery from any surgical procedure is different for everyone and depends on factors such as your age, general health and whether there were any complications during your surgery. Your consultant will be able to give you an estimated recovery timeline based on your individual circumstances.

After your surgery, you will be taken to the recovery room where you will be monitored closely until the effects of the anaesthetic have worn off. You may have some mild pain and tenderness and your arm may feel stiff for a few days after the procedure. Your healthcare team can recommend pain medication to manage this.

How many nights will I need to stay in hospital?

Sentinel lymph node biopsy is normally done as a day case, meaning you'll be able to go home later the same day.

Will I be able to drive home?

Due to the general anaesthetic, you will not be able to drive yourself home from the hospital, or for 24 hours after your sentinel lymph node biopsy. Please make arrangements for someone to collect you, or we can organise a taxi if you prefer.

How soon can I go back to work?

How soon you can go back to work after your surgery depends on how you feel after your procedure and the type of job you do. Most people return to work within two to seven days.

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After the first 24 hours, you can drive once you can safely control your vehicle and perform an emergency stop comfortably.

When will I be back to normal?

Recovery from any type of surgery is a gradual process that is different for everyone. You can help your recovery to go more smoothly by following your consultant's instructions carefully and taking things at your own pace as you recover. Most people can resume normal activities after around two weeks.

Dos and don'ts during your recovery


  • Build up your activity level gradually. Walk a little more each day and stop if you feel tired
  • Keep your surgical wound clean and dry
  • Take showers and gently pat the surgical area dry with a clean towel
  • Take painkillers if needed (Always read the patient information leaflet that comes with the medication carefully and ask your pharmacist if you have any questions)


  • Engage in activities that put a strain on your wound like cleaning windows, lifting heavy objects, vacuuming, or gardening
  • Take a bath or immerse your surgical wound in water for at least two weeks

Sentinel lymph node biopsy is a generally safe procedure, but as with all surgical procedures, there is a very small risk of complications. Your consultant will explain all the possible risks and complications before your procedure and answer any questions you may have to allow you to make an informed decision.

Possible complications of any surgery include:

  • Bleeding
  • Infection
  • Blood clots
  • Adverse reactions to the anaesthetic

Possible complications specific to sentinel lymph node biopsy include:

  • Pain - you may experience mild pain, tenderness, and stiffness around the area for the first couple of weeks. Taking over-the-counter painkillers like paracetamol and ibuprofen can normally help manage any pain
  • Numbness, tingling, swelling, or bruising - this normally resolves over time
  • Infection - infection of the surgical wound is treated with antibiotics
  • Allergic or skin reaction to the blue dye
  • Staining of the skin - the blue dye can stain the skin around the area for several months to a year. This is harmless and fades over time
  • Blue-green urine and faeces - as the blue dye is excreted from your body it can make your urine and faeces appear blueish. This is harmless and should resolve within 48 hours
  • Haematoma - this is a build-up of blood around the surgical wound. It normally goes away on its own but may need to be drained
  • Seroma - this is a collection of fluid around the wound. It usually settles without treatment, but in some cases may need to be drained
  • Scarring - scarring at the site where the biopsy was taken can develop causing tightness and discomfort. This usually improves within a few months
  • Lymphoedema - this occurs when the lymph cannot drain and builds up in your tissues causing swelling and pain. It is usually temporary, but in rare cases may be permanent

Call your doctor straight away if you have:

  • Pain that is getting worse or doesn't get better with painkillers
  • Fever ( a temperature of 38C or above)
  • Pain, redness, bleeding, or discharge from your surgical wound

You should receive the results of your biopsy within a week or two. Waiting for your results can be an anxious time and it's important to get support from friends and family during this period. Professional support and guidance from specialist cancer nurses is also available if you would like to talk to someone during this time. Let your healthcare team know if you would like us to arrange this.

If your result is negative

A negative result means that there were no cancer cells found in your biopsy. This means that your cancer is unlikely to have spread.

If your result is positive

A positive biopsy result means that your cancer has spread to your lymph nodes. Your consultant will discuss this result with you, including what will happen next such as further scans and treatments.

We answer some of your most commonly asked questions about sentinel lymph node biopsy.

What happens if my sentinel lymph node biopsy is positive?

If your sentinel lymph node biopsy is positive it means that cancer cells have spread from the main tumour to other parts of your body. Your consultant will explain what this means and discuss further tests and treatments with you at your next appointment.

How is a sentinel lymph node biopsy performed?

A sentinel lymph node biopsy is performed as a day case under general anaesthetic. Your consultant will make a small incision and locate and remove one or several lymph nodes before closing the incision. The lymph nodes are then sent to the laboratory to be checked for cancer cells.

How long does a lumpectomy and sentinel lymph node biopsy take?

A lumpectomy normally takes around 30-45 minutes. If you are having a sentinel lymph node biopsy at the same time, it will probably take an additional 45 minutes.

How long does it take to recover from lumpectomy and sentinel lymph node biopsy?

Recovery from lumpectomy and sentinel lymph node biopsy varies from person to person and depends on your individual circumstances. Most people can resume normal activities after around two weeks.

Is a sentinel lymph node biopsy painful?

Sentinel lymph node biopsy is performed under general anaesthetic meaning you'll be asleep during the procedure and won't feel any pain. You may experience some post-operative pain and tenderness around the surgical wound and arm stiffness for the first few weeks after your surgery. Taking over-the-counter painkillers like ibuprofen and paracetamol can help with this. Talk to your healthcare provider if your pain is severe, is getting worse, or isn't getting better after your procedure.

At Circle Health Group, we have the experience and expertise to ensure the best possible care and outcome for our patients. As a patient with Circle Health Group, you can expect the highest standards of care including:

  • Flexible appointment times and locations that are convenient for you
  • The freedom to choose which hospital and consultant suit your needs
  • Personalised, consultant-led treatment plans tailored to your individual needs
  • Comfortable and safe private facilities maintained by expert multidisciplinary teams
  • Private ensuite rooms as standard
  • A range of delicious healthy meals
  • Affordable, fixed-price packages with aftercare included
  • Flexible payment options to help you spread the cost of your care

If you would like to see a consultant or learn more about sentinel lymph node biopsy, book your appointment online today or call a member of our team directly.

Content reviewed by Circle in-house team in April 2023. Next review due April 2026.

  1. Sentinel lymph node biopsy, National Cancer Institute
  2. Sentinel lymph node biopsy, Cancer Research UK
  3. Surgery to the lymph nodes for breast cancer, Macmillan Cancer Support
  4. Sentinel Lymph Node Biopsy in Breast Cancer: A Work in Progress, PubMed

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