A fibroadenoma is the most common benign breast lump. It is due to proliferation of stromal (connective tissue) and epithelial tissue of the duct lobules.
🏘 Epidemiology
It usually occurs in women of reproductive age.
😷 Presentation
Once again it is a lump that may be:
- Highly mobile (“breast mouse”)
- Well-defined
- Rubbery
- Usually <5cm in diameter
These lumps may be unilateral or bilateral but they do not increase the risk for malignancy.
🧰 Management
They can be left in situ with follow up. 1/3rd will get smaller over 2 years. They can be surgically excised if >3cm or if the patient prefers.
Rule of 1/3rds:
- 1/3rd will get smaller
- 1/3rd will stay the same
- 1/3rd will get bigger
🔍 Investigations
As it is a breast lump, it will need to undergo triple assessment to ensure that it is a fibroadenoma and not a carcinoma. USS is usually conclusive.
- If <30 years old - routine referral to breast clinic.
- If >30 years old - urgent referral using 2 week wait pathway.
OTHER BENIGN BREAST TUMOURS
- Adenoma - benign glandular tumour. It usually occurs in older women. They may be nodular and similar to malignancy.
- Papilloma - benign tumour in the subareolar region. They may present with bloody/clear nipple discharge.
- Lipoma - soft and mobile mass of adipose tissue with low malignant potential.
- Phyllodes tumour - rare fibroepithelial tumour that occurs in older women. Once again made of epithelial and stromal tissue. 1/3rd have malignant potential and therefore should be excised (or mastectomy is indicated if they are large).