Can fibroadenoma be harmful in the future?

Fibroadenomas are usually benign (non-cancerous) tumors, but there is a very small chance that they can become cancerous. If a fibroadenoma is left untreated, it may continue to grow and become more noticeable. It's also possible for a fibroadenoma to rupture (break open), which can cause pain and bleeding. So although the vast majority of fibroadenomas are benign, it's important to have them checked by a doctor to make sure.