Seroma is a pocket of clear fluid which sometimes develops following surgery.
Seromas are very common after breast cancer surgical treatments, and also axillary surgery if there has been metastasis and lymph node involvement. Breast seromas can also occur after:-
- Breast reduction surgery
- Breast reconstruction surgery
- Breast biopsy surgery
- Plastic surgery
- Breast augmentation surgery (breast implant)
- Plastic reconstructive surgery
- Any other surgery in any part of the body including liposuction and body contouring surgeries.
A seroma may show up on follow-up imaging studies after treatment of breast cancer . So, seromas may possibly cause some initial concern about a developing ‘lesion’. However, more commonly, seromas are usually quite visible and palpable.
Seromas have no relation to ‘cancer cells’ and there is no increase in breast cancer risk whatsoever. But, seromas can complicate and extend the recovery period as the serous fluid may need draining.
Seromas may also increase the likelihood of ‘surgical site
seroma infection‘ (SSI). Doctors will treat and monitor seromas. However, seromas are not unique to the breast, but can develop anywhere in the body after any trauma or surgery. They are also seen following radiation therapy.
What causes a seroma?
There are a couple of different ways seromas form. Blood is essentially made from a combination of serum (which is part of the blood plasma and is liquid) and red blood cells. Sometimes the red blood cells ‘settle’ downward, causing separation from the serum. The serum then collects into a ‘seroma’.
Another way seromas develop is from ‘leaky’ blood vessels. If there is a tiny tear in the lining of a blood vessel or capillary, this allows the serum to escape, but not the red blood cells. Dying or injured cells can also trigger the inflammatory process which can contribute to the accumulation of serum fluid.
Seromas often ‘remain’ following a breast hematoma
Seromas are different from breast hematomas, which contain red blood cells, and breast abscesses which contain pus. However, sometimes seromas can ‘remain’ following the development of a hematoma or seroma. The ultrasound image above is likely one of these ‘remnant’ seromas following a hematoma.
How common is a seroma following breast cancer treatment?
There is a considerable difference of opinion as to the rate of seroma development. In addition, there is even more confusion regarding the possible factors that cause seromas.
Indeed, it is uncertain whether it is the treatment or patient characteristics, that might predispose a woman to developing a seroma post surgery.
From the available data, one might suggest the overall likelihood of developing seromas following breast cancer surgical treatment is between 16% and 35%. So, maybe 1 out of every 4 women or thereabouts.
There is really no way to predict this, and the only consistent factor influencing the likelihood of seromas seems to be the extent of the surgery.
Factors that influence the likelihood of developing Seromas following breast cancer surgical treatments
Scientists and clinical studies test many different ideas to try and see what factors influence the probability of seroma development.
Whilst many studies claim to have evidence of an increase in risk factors for developing breast seromas, the only factor which seems to have a consistent and verifiable bearing is the extent of the surgery.
So specialists estimate that a woman who undergoes a modified radical mastectomy (MRM or removal or breast) is about 2 to 3 times more likely to develop a seroma than a woman who has breast conserving surgery (BCS). This seems logical.
Other Unproven factors for seroma development
So, doctors consider many ideas as risk factors for developing seromas. These ideas include just about every conceivable aspect of the procedure and the patient.
Some clinical studies have looked at factors of the blood, these include:-
- Blood transfusion
- Blood loss during surgery.
Others studies consider the technical aspects of the surgery itself. These include the:-
- Type of scalpel
- Angle of the incision
- Various aspects of suturing
- Latissimus dorsi flaps
- Use of ‘adhesive glues’
- Type and pressure of the dressing
- Whether the area is immobilized
- Amount of time that the area is immobilized (for shoulder surgeries)
- Length of the operation
- Type of seroma drainage (closed suction drain versus static drain, multiple channel vs. multiple holes)
- Use of a fibrinolysis inhibitor.
Only the severity of breast surgery has a proven bearing on seroma development
Other studies suggest that the risk of seromas following breast cancer surgical treatment may increase if the patient has an underlying condition. For example, hypertension, diabetes or a history of breast biopsies.
Studies have also looked at radiation treatment and neoadjuvant chemotherapy therapies.
Also, studies have examined specific histological features including:-
- The size and grade of tumor
- Hormone receptor status
- Lymph node status (positive or negative for breast cancer metastasis)
- Number of lymph nodes removed (in axillary surgery)
In addition, medics have considered more general health issues that may increase the risk for seromas and these include:-
- Size of the breasts
- Body weight
- Again, none of the above factors have been proven to have any consistent influence on the risk of seromas, with the exception of severity of surgery. Modified Radical Mastectomy (MRM) versus Breast-conserving Surgery (BCS)
Treatments of seroma
The good news is that the body will gradually re-absorb seromas. So, most surgeons view seromas as an unavoidable nuisance rather than a serious complication.
However, the reabsorption can take many days or even weeks. Sometimes a ‘knot‘ of calcified soft tissue remains after the seroma has dissipated. This calcification may show up on follow-up imaging studies, but is of no health concern whatsoever.
However, sometimes the accumulation of fluid in a seroma can be excessive, causing the skin to stretch and to sag causing a skin flap. This can be uncomfortable for the patient and prolong the recovery time in hospital and the general healing process. In these situations your doctor may drain the seroma by fine-needle aspiration, but this can take several attempts.
In more serious cases, where there is wound dehiscence, it may be necessary for incision and drainage.
Seromas versus hematoma, is kind-of decided once you aspirate the fluid into a syringe, and see the color. If the fluid is yellow, call it a seroma. If very red, call it hematoma. In-between, call it whatever you want.
Yes, they gradually go away without aspiration. Yes, things get back to normal quicker if they are aspirated.
Questions and Answers
Where does the fluid in seromas come from?
Sometimes the fluid is from a hematoma (bleeding) that separates into blood clots and yellow fluid (serum). Other times, it’s a leak of yellow fluid (lymphatic fluid) from the tissues, “just because”. Because why? I guess something made capillaries leaky. The capillary endothelial cells lining the blood vessels got sick. How? Maybe during surgery, the tissues were compressed , or their blood supply was interrupted.
When will seroma go away?
Eventually, or sooner if someone will agree to aspirate it. Do seromas return? Yes, but usually much smaller the second time.
How to avoid a seroma?
I believe direct hand pressure on wounds is the best. I believe tissues wounded by surgery then stitched together, should not be massaged or pushed in different directions. You have to give time, for undisturbed cut tissue edges to rejoin to each other otherwise there could be a problem on suture removal.
Are seromas dangerous?
Are seromas painful?
Yes, often they stretch the surrounding tissue, stretching nerve endings, which send complaining signals to the brain, which the brain interprets as pain.
Can Seromas be avoided?
Seromas are less likely to occur if a small drain is placed at the wound site on surgery and removed when any fluid stops draining. However, seromas can still occur after drain removal.
What are the signs and symptoms of seroma?
Seroma symptoms include swelling at, or near, the wound site with leakage of clear or yellowish fluid. Sometimes this is accompanied by redness and mild pain (or tenderness) at the site. Seromas often appear as a large lump or a large cyst. If a seroma is not regularly drained it can sometimes cause a hardened lump of scar tissue.
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