A fibroadenoma is a common, non-cancerous breast lump that develops from the overgrowth of glandular and connective tissue. These masses are generally harmless and occur most frequently in women aged 15 to 35. The presence of a fibroadenoma typically does not prevent or significantly impede a mother’s ability to breastfeed successfully.
How Fibroadenomas Respond to Lactation
Fibroadenomas are highly sensitive to the hormonal shifts that occur during late pregnancy and the postpartum period. These masses contain receptors for hormones like estrogen and progesterone, which significantly increase. This hormonal stimulation causes the fibroadenoma tissue to undergo lactational change or secretory hyperplasia.
This change often results in the fibroadenoma increasing in size, sometimes becoming noticeably larger or more tender. Rapid growth can occasionally lead to tissue death within the mass, a process called infarction, which may cause pain or lead to a more solid texture. The internal structure may also begin to show small calcifications or dilated milk ducts, similar to the changes seen in the surrounding breast tissue. These physical changes are a normal physiological response but warrant medical evaluation.
Direct Impact on Milk Supply and Delivery
The lack of interference with nursing is due to the fibroadenoma’s typical location and structure within the breast. Fibroadenomas are connective tissue tumors that usually grow outside of the major milk duct system. They arise from the tissue supporting the breast and the cells lining the milk ducts, but they do not generally create a blockage within the main ducts.
Consequently, a fibroadenoma rarely reduces the overall milk volume or supply from the affected breast. If the mass is particularly large (over five centimeters) or situated near the nipple-areolar complex, it might compress some surrounding milk-producing tissue. Any reduction in supply is usually localized to the area of compression, rather than the entire breast.
A mother may experience blocked ducts or localized tenderness near the mass, which could be a coincidence or due to the mass slightly impeding milk flow. The milk produced by the breast with a fibroadenoma is completely safe for the baby to consume. Discomfort that makes latching difficult can often be managed by adjusting nursing positions to avoid direct pressure on the lump.
Monitoring and Treatment While Breastfeeding
For a mother with a known fibroadenoma, continued monitoring throughout the nursing period is standard. If a new lump is discovered or an existing one changes rapidly, evaluation typically begins with an ultrasound. This imaging technique is safe during lactation and effectively distinguishes a solid mass, like a fibroadenoma, from a fluid-filled cyst.
If the mass has suspicious features on imaging, a core needle biopsy may be recommended to confirm its benign nature. This procedure is safe during lactation and does not require interrupting nursing. Local anesthetics, such as lidocaine, are used during the biopsy, and the negligible amount entering the milk supply means there is no need to “pump and dump” the milk.
Surgical removal of a fibroadenoma is often delayed until after weaning, unless the mass is growing rapidly, causing significant pain, or raising concern for a complex lesion. Waiting allows the breast tissue to return to its non-lactating state, simplifying the procedure. This also minimizes the small risk of developing a milk fistula, a rare complication where milk leaks from the incision site. Mothers who notice changes in the lump, persistent pain, or recurrent blockages should consult with their obstetrician, radiologist, or a lactation consultant.