Fibroadenomas are solid breast lumps or masses that usually are:

  • Round with distinct borders
  • Easily moved
  • Firm or rubbery
  • Painless

A fibroadenoma may feel like a marble within your breast when you press on it. You can have one or many fibroadenomas. The average fibroadenoma is about an inch (2.5 centimeters) in diameter. Those larger than 2 inches (5 centimeters) are called giant fibroadenomas.

Fibroadenomas first occurring during adolescence are called juvenile fibroadenomas. They can grow rapidly and become as large as 4 inches (10 centimeters) in diameter.

When to see a doctor

Normal breast tissue in healthy women often feels lumpy. If you detect any new breast lumps — or if a previously evaluated breast lump seems to have grown or otherwise changed — make an appointment with your doctor to get it checked out.

May. 27, 2011