What is a fibroadenoma?

A fibroadenoma is a benign breast condition due to overgrowth of the tissue supporting the breast and cells lining the milk ducts. 

Who gets fibroadenomas?  

Fibroadenomas have been reported in around 10% of the female population. They are most common in the 21 to 25 year age group. Less than 5% occur in women over age 50. 

What are the symptoms of fibroadenomas?

Breast lump

Fibroadenomas may form a lump in the breast. The lump is usually oval or round, smooth, firm and moves freely. Fibroadenomas have been referred to as 'breast mice' as their ability to move so freely gives the feeling that they are running away from the examining hand. 

Breast pain 

Fibroadenomas can be painful, especially prior to a period. 

Can fibroadenomas grow?

The 'rule of thirds' can be applied to fibroadenomas. If left alone, one third will decrease in size (or even disappear), one third will increase in size and one third will remain the same. Fibroadenomas can grow during pregnancy and breastfeeding and while taking hormone replacement therapy.

Do fibroadenomas cause cancer?

Fibroadenomas are not cancerous and having one does not significantly increase the risk of developing breast cancer. Fibroadenomas contain some normal breast tissue cells and these cells can develop cancer like all cells in the breast. 

How are fibroadenomas diagnosed?

The diagnosis of a fibroadenoma can be confirmed through a biopsy, usually under ultrasound guidance. 

Small lesions that look like fibroadenomas may not require biopsy and can be monitored with ultrasound.

What is the treatment for fibroadenomas?

Surgery is recommended for fibroadenomas that are painful, larger than 3 cm in size (or increasing in size) or show worrying features on imaging or biopsy. 

Fibroadenomas that are not removed surgically are monitored with ultrasound for a period of time.