You notice a breast lump or bruising after an injury, biopsy, surgery, or procedure.
Your ultrasound report mentions:
“Hematoma.”
A breast hematoma is a collection of blood within the breast tissue.
Most hematomas are benign and gradually resolve as the body absorbs the blood.
But there is one reason they can be confusing:
A hematoma can look very different on ultrasound depending on when it formed.
As it heals, its appearance may change significantly.
What Is a Breast Hematoma?
A hematoma forms when blood vessels are damaged and blood collects within the surrounding tissue.
In the breast, this can occur after:
- Trauma
- Breast biopsy
- Breast surgery
- Needle procedures
- Breast implants or reconstruction
- Significant pressure or injury
Sometimes a person does not remember a specific injury.
What Does a Breast Hematoma Feel Like?
A breast hematoma may feel like:
- A tender lump
- A firm area
- Localized swelling
- A painful mass
- An area of fullness
The skin over the area may also show bruising.
Depending on the amount of bleeding, the breast may feel swollen or heavier than usual.
What Does a Breast Hematoma Look Like on Ultrasound?
There is no single ultrasound appearance of a hematoma.
Its appearance depends largely on its age.
A hematoma may appear:
- Hyperechoic
- Hypoechoic
- Heterogeneous
- Complex cystic
- Predominantly fluid-filled
This is because blood changes as it clots, liquefies, and is gradually absorbed.
Why Does a Hematoma Change on Ultrasound?
Fresh blood and older blood do not look the same.
Early stage
A recent hematoma may contain clotted blood and appear relatively solid or echogenic.
Intermediate stage
As the blood begins to break down, the lesion may become more heterogeneous or complex.
Later stage
The contents may become increasingly fluid-like as the blood liquefies.
Eventually, the hematoma may:
- Shrink
- Resolve
- Leave scar tissue
- Develop fat necrosis
This evolution over time can be an important clue.
Does a Hematoma Have Blood Flow on Doppler?
A simple hematoma generally should not have true internal vascularity because it consists of collected blood rather than living solid tissue.
Color Doppler may therefore help during evaluation.
However, surrounding tissue may demonstrate blood flow, particularly when inflammation or healing is present.
A solid component with convincing internal vascularity may require closer assessment.
Doppler is helpful, but it should never be interpreted alone.
Can a Breast Hematoma Look Like a Solid Mass?
Yes.
This is particularly possible when blood has recently clotted.
An acute hematoma can sometimes appear relatively solid on ultrasound.
Clinical history becomes very important.
A new mass appearing shortly after:
- Trauma
- Surgery
- Biopsy
may fit with a hematoma.
But history alone is not enough if the imaging appearance is concerning.
Breast Hematoma vs Simple Cyst
Both can eventually contain fluid, but they are different.
Simple cyst
Usually:
- Anechoic
- Thin-walled
- Circumscribed
- Shows posterior enhancement
- Contains simple fluid
Hematoma
May:
- Contain blood products
- Have internal echoes
- Look heterogeneous
- Change significantly over time
- Occur after trauma or a procedure
A hematoma often has a much more variable appearance.
Breast Hematoma vs Breast Cancer
A hematoma may occasionally mimic a breast mass, particularly when the clinical history is unclear.
Features that can make evaluation more difficult include:
- Irregular appearance
- Heterogeneous internal echoes
- Palpable firmness
- Persistent abnormality
When a lesion has suspicious features or does not behave as expected over time, further evaluation may be necessary.
This may include:
- Follow-up ultrasound
- Diagnostic mammography
- Additional imaging
- Biopsy
A history of trauma should not automatically override suspicious imaging findings.
Can a Hematoma Turn Into Breast Cancer?
No.
A breast hematoma does not turn into breast cancer.
It is a collection of blood caused by damaged vessels.
However, a breast lump should not automatically be called a hematoma without appropriate clinical or imaging evidence.
If an unexplained mass persists, further evaluation may be appropriate.
Can a Hematoma Lead to Fat Necrosis?
Yes.
Damage severe enough to cause bleeding can also injure surrounding fatty tissue.
As the area heals, fat necrosis may develop.
Fat necrosis may later produce:
- An oil cyst
- Fibrosis
- Calcification
- A persistent palpable lump
So an area that originally looked like a hematoma may appear quite different on later imaging.
How Long Does a Breast Hematoma Take to Go Away?
The healing time varies.
Small hematomas may improve over several weeks.
Larger hematomas can take considerably longer to shrink and may remain visible on imaging for months.
Factors include:
- Size
- Amount of bleeding
- Medications
- Location
- Whether additional tissue injury occurred
The important point is that the lesion should generally evolve in a way consistent with healing.
Can Blood-Thinning Medication Cause a Breast Hematoma?
Blood-thinning medications can make bruising or bleeding more likely after trauma or procedures.
This includes certain:
- Anticoagulants
- Antiplatelet medications
If you develop significant breast swelling or bruising while taking these medications, contact your healthcare professional.
Do not stop prescribed medication without medical guidance.
Does a Breast Hematoma Need Treatment?
Most small, uncomplicated breast hematomas do not require invasive treatment.
Management may include observation while the body gradually absorbs the blood.
Larger or symptomatic hematomas may occasionally require additional management.
The appropriate treatment depends on:
- Size
- Symptoms
- Active bleeding
- Infection
- Clinical circumstances
Should I Massage a Breast Hematoma?
Avoid aggressively massaging a new or painful breast hematoma unless your healthcare professional specifically recommends it.
Additional pressure may worsen discomfort and may not help an acute injury.
Follow the advice provided for your specific situation.
Can a Hematoma Become Infected?
Occasionally, a collection can become infected.
Seek medical evaluation if you develop:
- Increasing redness
- Warmth
- Worsening pain
- Fever
- Drainage
- Rapidly increasing swelling
These symptoms may indicate infection or another complication.
When Should a Breast Hematoma Be Re-Evaluated?
Consider reassessment if:
- The lump does not decrease
- It continues to enlarge
- Pain becomes worse
- The breast becomes increasingly swollen
- Redness or warmth develops
- There was no clear trauma or procedure
- The palpable abnormality persists longer than expected
- New skin or nipple changes appear
A presumed hematoma that does not behave like a resolving hematoma deserves another look.
What If I Have a Lump After a Breast Biopsy?
A small hematoma after a breast biopsy is not unusual.
You may notice:
- Bruising
- Tenderness
- A small palpable lump
- Mild swelling
These symptoms generally improve.
Contact your healthcare provider if you experience rapidly increasing swelling, significant bleeding, severe pain, fever, or other concerning symptoms.
What Should I Look for in My Ultrasound Report?
If your report mentions a hematoma, useful information may include:
- Size
- Location
- Recent trauma or procedure
- Internal appearance
- Vascularity
- Comparison with previous imaging
- BI-RADS assessment
- Follow-up recommendation
Follow-up imaging may sometimes be used to confirm that the finding changes or resolves as expected.
The Bottom Line
A breast hematoma is a benign collection of blood within the breast, commonly occurring after:
trauma + biopsy + surgery + other procedures
Its ultrasound appearance changes as the blood ages:
fresh blood → clot → liquefaction → resolution
and in some cases:
healing → fat necrosis
Most hematomas gradually improve.
But if a presumed hematoma grows, persists, has no clear cause, or does not evolve as expected, further evaluation may be appropriate.
The history matters — but so does what happens to the finding over time.
About the Author
I’m a sonographer with over 20 years of hands-on clinical ultrasound experience, working across breast, thyroid, and obstetric imaging.
Through UltrasoundNote, I share practical, easy-to-understand information based on real-world ultrasound experience to help patients better understand their imaging and breast health.
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment.
