Galactocele
A benign milk-filled cyst that forms in the breastfeeding breast
Quick Facts
- Type: Benign breast cyst
- Most common in: Women who are or recently were breastfeeding
- Main cause: Blocked milk duct
- Cancer risk: Not cancerous and does not raise cancer risk
Overview
A galactocele is a smooth, milk-filled cyst that forms inside the breast, most often during or shortly after a period of breastfeeding. It develops when a milk duct becomes blocked and milk collects behind the blockage, gradually forming a soft, fluid-filled sac. Galactoceles are the most common benign breast lump in women who are lactating.
Although finding any new breast lump can be worrying, a galactocele is harmless. It is not cancer and does not increase the risk of breast cancer. Many galactoceles shrink or resolve on their own once breastfeeding ends, and most that need treatment are easily managed by draining the fluid.
Symptoms
A galactocele usually appears as a single, painless lump, though some people notice more than one. Typical features include:
- A soft, smooth, round or oval lump that can often be moved slightly under the skin
- Location anywhere in the breast, though often near the nipple or center
- A lump that may change in size, sometimes feeling fuller before a feeding
- Occasionally, a milky or oily fluid that can be expressed from the nipple
Galactoceles are not usually painful or warm. If a lump becomes red, hot, tender, or is accompanied by fever, this may signal an infection and should be evaluated promptly.
Causes
A galactocele forms when a milk duct is blocked and milk backs up behind it. Over time the trapped milk thickens and is enclosed in a cyst. Several factors related to lactation contribute:
- Duct blockage: A plugged or narrowed duct prevents milk from draining normally.
- Weaning or reduced feeding: Galactoceles often appear when breastfeeding slows or stops and milk is no longer fully emptied.
- Hormonal changes: The hormonal shifts of pregnancy and lactation drive milk production and can promote retention.
Rarely, galactoceles occur in infants or in people who are not breastfeeding, usually linked to hormonal influences or certain medications that raise prolactin levels.
Risk Factors
- Current or recent breastfeeding
- Recent weaning or a sudden drop in feeding frequency
- A history of blocked ducts or mastitis
- Less commonly, medications or conditions that raise prolactin levels
Diagnosis
A doctor can often suspect a galactocele from the history and a physical exam, but imaging is used to confirm it and rule out other causes of a breast lump:
- Breast ultrasound: The first-choice test, especially in younger and breastfeeding women, showing a fluid-filled cyst.
- Mammography: May be used in some cases; a galactocele can have a characteristic fat-fluid appearance.
- Needle aspiration: Drawing fluid with a fine needle both confirms the diagnosis (milky fluid) and can relieve the lump at the same time.
Treatment
Many galactoceles need no treatment and resolve on their own, particularly once breastfeeding ends. When treatment is wanted or needed, options include:
- Needle aspiration: Draining the milky fluid with a fine needle is simple, confirms the diagnosis, and relieves the lump. The cyst can sometimes refill.
- Continued breastfeeding and good drainage: Frequent feeding or pumping and gentle massage can help clear a blocked duct.
- Surgical removal: Rarely needed, this is considered only if a galactocele keeps coming back, becomes infected repeatedly, or the diagnosis is uncertain.
If a galactocele becomes infected, antibiotics and drainage may be required.
Prevention
- Breastfeed or pump regularly and fully empty the breasts
- Avoid sudden, abrupt weaning when possible; reduce feeds gradually
- Address blocked ducts early with frequent feeding, warmth, and gentle massage
- Wear a comfortable, well-fitting bra that does not compress the breast
When to See a Doctor
Have any new breast lump checked by a healthcare professional, even if you think it is a galactocele, so other causes can be ruled out. Seek prompt care if you notice:
- Redness, warmth, swelling, or tenderness over the lump
- Fever or feeling generally unwell, which may signal infection
- A lump that is hard, fixed in place, or keeps growing
- Skin dimpling, nipple changes, or bloody nipple discharge
Frequently Asked Questions
Is a galactocele cancerous?
No. A galactocele is a benign, milk-filled cyst and is not cancer. It also does not raise your risk of breast cancer. Even so, any new breast lump should be checked so other causes can be ruled out.
Will a galactocele go away on its own?
Many galactoceles shrink or disappear on their own, especially once breastfeeding stops and milk production decreases. If a lump is bothersome or the diagnosis is uncertain, a doctor can drain it with a fine needle.
Can I keep breastfeeding with a galactocele?
Yes, breastfeeding is generally safe and can even help by keeping milk flowing and clearing blocked ducts. Frequent feeding, gentle massage, and warmth often improve drainage.
How is a galactocele different from mastitis?
A galactocele is a painless milk-filled cyst, while mastitis is an infection or inflammation that causes a red, warm, painful breast, often with fever. If your lump becomes red, hot, and tender, see a doctor, as it may be infected.
What happens if a galactocele gets infected?
An infected galactocele can become red, warm, and painful and may be treated with antibiotics and drainage of the fluid. Seek care promptly if you develop these signs along with fever or feeling unwell.
References
- Mayo Clinic. Breast lumps and breast cysts.
- MedlinePlus, U.S. National Library of Medicine. Breast lumps.
- American College of Obstetricians and Gynecologists (ACOG). Benign breast conditions.
- Office on Women's Health, U.S. Department of Health and Human Services. Breastfeeding.