Fibroadenoma of the Breast

Michigan Breast Specialists


Causes, incidence, and risk factors

Fibroadenoma of the breast is a noncancerous (benign) tumor. It is the most common benign tumor of the breast and the most common breast tumor in women under age 30.

Most of the time they present as a lump in the breast, but they can also be found incidentally on a mammogram exam.

A fibroadenoma is made up of breast gland tissue and fibrous issue that helps support the breast gland tissue. It is considered a proliferative breast lesion. The exact cause of fibroadenomas is unknown. They seem to be influenced by estrogen, because they appear most often in premenopausal or pregnant women.

Black and Asian women tend to develop fibroadenomas more often and at an earlier age than white women.  Increasing age reduces the risk of development.

Symptoms

Fibroadenomas are usually single lumps, but about 10 - 15% of women have several lumps develop in both breasts.

Lumps may be:

  • Easily moveable under the skin
  • Firm
  • Painless
  • Rubbery
  • Tender

They have smooth, well-defined borders. They may grow in size, especially during puberty and pregnancy. Fibroadenomas often get smaller after menopause (if a woman is not taking hormone replacement therapy).

Signs and tests

After the physical examination, a breast ultrasound is advised which generally  shows  a  classical appearance of a well-defined solid mass with  defined edges.

A core needle biopsy must be performed to get a definite diagnosis. Women in their teens or early 20s may not need a biopsy if the lump does not change over a long period of time.

Treatment

If a biopsy shows that the lump is a fibroadenoma, the lump may be left in place, or removed.

The decision to remove the lump is made by the patient and the surgeon. Reasons to have it removed include:

  • Abnormal biopsy results, with other cells mixed with the fibroadenoma.
  • Increased tenderness.
  • The mass has increased in size, especially if over one inch ( 2 centimeters) in size.

If the lump is left in place, it may be watched over time with:

  • Physical examination
  • Ultrasound

Expectations (prognosis)

Lumps that are not removed should be checked regularly by physical exams and imaging tests, following the doctor's recommendations.

If the lump is left in place and carefully watched, it may need to be removed at a later time if it changes, or grows.

Dangerous signs

  • Sudden increase in size of tumor
  • Pain in breast not affected by menstrual cycle
  • Hard, immovable tumors
  • Change in color of the skin

Call Michigan Breast Specialists at 313-647-3900 if you have a lump that grows or changes in any way.