An Overview of Breast Seromas

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Sometimes, after trauma to the breast or a procedure like breast surgery or radiation therapy, serous fluid can collect in one area of the breast. This is called a breast seroma.

Serous fluid is a clear, pale yellow fluid that contains protein but no blood cells or pus. Seromas are usually reabsorbed by the body over a period of several weeks, but fine needle drainage is sometimes needed.

Seromas do not increase the risk of breast cancer, but sometimes scar tissue or calcifications form when they heal. Both of these can bring up concerns on future mammograms.

Read on to find out more about symptoms, causes, and treatment of breast seromas.

Doctor is working with mammography X-ray scanner in hospital
praetorianphoto / Getty Images


The symptoms of a seroma usually appear a week to 10 days after trauma, biopsy, surgery, or after surgical drains have been removed, but this can vary. Sometimes symptoms occur very soon after an injury or procedure, and other times, they can become a problem several weeks later.

Initially, the area may feel tender and swollen, with a defined lump and redness arising within a day or two. The lump may feel squishy and quite sore.


In addition to causing pain, a seroma increases your risk of developing an infection in the breast, but this is less common. Depending on the location, it may also increase pressure over the surgical site and can sometimes pull the incision apart (what's known as wound dehiscence). When seromas occur shortly after surgery, they may add time to your hospital stay.

When a seroma heals, it may leave behind scar tissue that can sometimes be difficult to distinguish from cancer on mammography. This can lead to false-positive tests.

When present for a significant period of time, a seroma can also stretch the skin, which can lead to sagging later on.

The development of lymphedema can also occur. This is a blockage of lymph ducts that causes a potentially uncomfortable or painful buildup of fluid. Research shows that seromas roughly double the risk of lymphedema after breast cancer surgery.

Seromas and Breast Cancer Risk

Seromas do not increase your risk of developing breast cancer, but they may raise concern due to their appearance on exam or imaging studies.


Researchers suspect seromas are the result of an inflammatory response related to fluid build-up. They can develop nearly anywhere in the body following surgery.

Breast seromas are especially common, with a 2014 study reporting that computed tomography (CT) scans six months after breast cancer surgery revealed evidence of a seroma in 20% of participants.

Risk Factors

Risk factors for breast seromas include:

While a seroma may develop after any kind of breast surgery or even a biopsy, only a few factors are associated with an increased risk, including the extent of surgery (they are more common after a mastectomy than a lumpectomy), how long the surgery took, and the number of lymph nodes removed.

Seromas are more common when surgical drains aren't used, but using drains doesn't fully eliminate the risk.

It's important to call your healthcare provider if you develop a lump after an event that can lead to a seroma or any time you notice a lump in your breast.


Breast seromas can often be felt or even seen when the breast is examined. Since they can form a lump you can feel, they frequently raise concerns that cancer has come back or wasn't completely removed during surgery.


Ultrasound is often the best tool to identify a seroma. The fluid pocket shows up as a dark area. If a seroma becomes calcified, it will be visible on a mammogram.

Differential Diagnosis

A few conditions may appear similar to a seroma during an exam. These include:

  • Breast hematomas: Hematomas in the breast are collections of blood instead of serous fluid, but have similar risk factors to seromas. In addition, seromas and hematomas may occur together.
  • Lymphoceles: A collection of lymph fluid may appear similar to a seroma.
  • Abscesses: Areas of infection that become walled off may also appear similar to a seroma, though the contents are different.


Most often, seromas go away on their own over time as the body reabsorbs the fluid. This process takes roughly a month, on average, but in some cases, it can take up to a year. Seromas don't need to be treated unless they're causing problems such as pain or pressure, or if they're growing.

Needle Drainage

Fine needle aspiration is the approach of choice to remove fluid from a seroma that is painful or persistent. In this procedure, the skin is numbed with a local anesthetic, and then a healthcare provider inserts a long, thin needle through the skin and into the seroma to drain the fluid.

Needle aspiration can increase the risk of infection, so it's important to weigh the risks and benefits of waiting versus having a seroma drained.

Seroma fluid can build up again after drainage, so the procedure may need to be repeated.

Home Remedies and Treatments

Applying heat via a heating pad or warm, moist compresses can help encourage the fluid to drain, speed the healing process, and reduce pain.

It's also important to keep the skin overlying a seroma clean, especially after fine needle aspiration.

When to Call Your Healthcare Provider

If you've already had a seroma diagnosed, be sure to call if:

  • The area around your seroma becomes red or swollen
  • You notice any discharge
  • The seroma increases in size
  • You develop a fever

Since seromas increase the risk of lymphedema, it's also important to follow any recommendations your healthcare provider gives you, such as avoiding blood draws and blood pressure readings on the side of your body where the breast cancer was removed.


Surgeons have been studying which surgical techniques are best to reduce the incidence of seromas. Electrocautery used in surgery to prevent blood loss seems to increase the risk as it causes heat damage to the tissues. Surgeons must balance the risk of seroma with the effectiveness of cautery in preventing bleeding. Two small studies, one published in 2019 and one in 2017, suggested that a certain suturing technique could minimize seroma formation.

A few clinical trials have looked at the use of a low-thrombin fibrin sealant glue after lymph node surgery with breast cancer, and at one time this was thought to reduce the risk of seromas. However, a 2017 study did not find this approach helpful in reducing seromas, though it was associated with shorter hospitalizations.

Surgical Drains

Surgical drains (closed suction drains) can reduce the risk of seroma formation, but they also increase the risk of infection when left in place for an extended period of time. Many surgeons err on the side of not removing drains too rapidly after surgery.

Shoulder Movement

Early movement of the shoulder may increase the risk of seroma formation, but delaying movement also increases risk. It's important to talk to your surgeon about recommendations regarding movement after surgery.


Compression bandages were often used in the past to prevent seromas, but this practice is much less common now. Still, patients are often encouraged to wear a firm-fitting bra or another garment after surgery.


If you've had breast cancer, the hardest part about coping with a seroma is likely the worry it can cause over cancer coming back. Getting lumps checked out right away can help ease your mind as well as catch any reoccurrence quickly.

If you have a painful seroma, it can make wearing a bra difficult. You may want to experiment with different fits and tightnesses to see what's most comfortable.

Be sure to talk to your healthcare provider if you find a seroma is causing you problems, physically or emotionally.


Breast seromas are pockets of serous fluid that are generally nothing to worry about. They do not increase the risk of breast cancer. While many resolve on their own, if one does not, there are treatments available. These include fine needle aspiration and applying heat at home. If you have a seroma and it is not going away or it is causing you distress, talk with your healthcare provider about what can be done.

While many seromas resolve on their own and are fairly easy to treat if they don't, they can cause pain and significant anxiety at a time when many people are already feeling apprehensive. When possible, prevention is the best treatment, and it's important to talk to your healthcare provider about her recommendations for movement and drains after surgery and the reasons behind them.

Frequently Asked Questions

  • How do you make a seroma go away?

    If a seroma does not go away on its own, it can be treated using fine needle aspiration. This procedure numbs the affected area and drains the seroma's fluid using a very thin needle. Multiple appointments may need to be scheduled if the seroma fluid reappears. Using a heating pad or warm and moist compress after drainage can help with recovery and pain management.

  • What happens if a seroma is left untreated?

    If a seroma does not resolve on its own (which can take up to a year or more), there is a possibility it can become infected. However, if it is not causing problems, there is generally no need for concern. Talk with your healthcare provider if it does not seem to be resolving.

  • Is a seroma common after breast augmentation?

    Seromas can occur after breast surgery, including augmentation. Multiple factors may come into play, like the extent and duration of the surgery. Prior to your surgery, talk with your healthcare provider about ways to reduce the risk of seromas forming, including how you should move your shoulder after surgery. It's said that some delay in physical therapy after a procedure can lower the risk of a seroma forming.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. OncoLink. Seroma.

  2. Cancer Treatment Centers of America. Seroma.

  3. Toyserkani NM, Jørgensen MG, Haugaard K, Sørensen JA. Seroma indicates increased risk of lymphedema following breast cancer treatment: A retrospective cohort study. Breast. 2017;32:102-104. doi:10.1016/j.breast.2017.01.009

  4. Axelsson CK, Qvamme GM, Okholm M, et al. Bacterial colonization of seromas after breast cancer with and without local steroid prophylaxis. World Journal of Surgical Oncology. 2019;17. doi:10.1186/s12957-019-1661-1

  5. Park SY, Kim EY, Park HK, et al. Computed tomographic findings of postoperative seroma in breast cancer patients. J Breast Dis. 2014;2(2):64-68. doi:10.14449/jbd.2014.2.64

  6. Ebner F, Friedl TWP, De Gregorio A, et al. Seroma in breast surgery: all the surgeons fault? Arch Gynecol Obstet. 2018;298(5):951-959. doi:10.1007/s00404-018-4880-8

  7. Srivastava V, Basu S, Shukla VK. Seroma formation after breast cancer surgery: what we have learned in the last two decades. J Breast Cancer. 2012;15(4):373-80. doi:10.4048/jbc.2012.15.4.373

  8. Arafa AS, Fayek F, Awad JR. Efficacy of mastectomy flap fixation in minimizing seroma formation after breast cancer surgery. Egypt J Surg. 2019;38(4):656-661. doi:10.4103/ejs.ejs_57_19

  9. Zaidi S, Hinton C. Breast cancer surgery without suction drainage and impact of mastectomy flap fixation in reducing seroma formation. Eur J Surg Onc. 2017;43(5):S32. doi:10.1016/j.ejso.2017.01.129

  10. Conversano A, Mazouni C, Thomin A, et al. Use of low-thrombin fibrin sealant glue after axillary lymphadenectomy for breast cancer to reduce hospital length and seroma. Clin Breast Cancer. 2017;17(4):293-297. doi:10.1016/j.clbc.2016.12.013

Originally written by Pam Stephan
Pam Stephan is a breast cancer survivor.
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