Presentation
Good morning, sir. I examined the breasts of a 22-year-old undergraduate, with a chaperone present, who noticed a painless lump in her right breast while bathing three months ago. It has not changed in size or with her periods, and she has no nipple discharge, family history of breast cancer, or use of hormonal contraception. The breasts are symmetrical, with no skin or nipple changes in any position. There is a single, 2.5 × 2 cm lump in the upper outer quadrant of the right breast at 10 o'clock, 4 cm from the nipple. It is non-tender, spherical, smooth, rubbery and well defined, and it slips away readily under the fingers. It is not attached to the skin or to pectoralis major. There are no axillary or supraclavicular lymph nodes. The left breast is normal. These findings are in keeping with a fibroadenoma of the right breast.
Diagnosis
A solitary, clinically benign lump in the right breast of a young woman, most likely a fibroadenoma.
Differential diagnoses
- Phyllodes tumour — older (usually over 35–40), larger, rapid growth, lobulated; may look like a fibroadenoma on imaging
- Breast cyst — commoner aged 35–55; smooth, tense, may be tender; anechoic on ultrasound
- Localised fibroadenosis (nodularity) — ill-defined, varies with the menstrual cycle, often bilateral
- Carcinoma — uncommon at this age but not impossible; hard, irregular, fixed; BRCA carriers
- Lipoma — soft, lobulated, slip sign
- Galactocele — during or after lactation; milky aspirate
- Fat necrosis — history of trauma
- Tuberculous or granulomatous mastitis — tender, inflammatory, sinus
Investigations
| Test | What you expect or look for |
|---|---|
| Breast ultrasound (first-line under 35) | Well-circumscribed, oval, homogeneous, hypoechoic solid mass, wider than tall, with a thin echogenic capsule |
| Mammography | Not routine under 35 (dense breasts, radiation); in older women may show "popcorn" calcification in an involuting fibroadenoma |
| Ultrasound-guided core biopsy | Fibroadenoma — mixed epithelial and stromal proliferation without stromal overgrowth or atypia |
| MRI | Only for BRCA carriers or uncertain findings |
In women under 25 with a clinically and sonographically typical fibroadenoma under 3 cm, many units accept ultrasound alone without biopsy. Biopsy if there is any atypical feature, the woman is over 25, there is a family history, or the lump is growing.
Types of fibroadenoma
| Type | Features |
|---|---|
| Simple | Commonest; under 3 cm |
| Complex | Contains cysts, sclerosing adenosis, calcifications or papillary apocrine change; slightly higher cancer risk |
| Juvenile | Adolescents; rapid growth; cellular stroma |
| Giant | Over 5 cm or over 500 g; distorts the breast; any age but often adolescent |
Management
I would reassure her that this is a benign condition that does not turn into cancer and that she does not need an operation unless she wishes, or it grows or causes symptoms. I would give her the choice.
Non-pharmacological
- Reassurance and observation — about a third shrink or disappear over 2 years, especially in young women
- Breast awareness: return if it grows or changes
- Repeat clinical examination and ultrasound in 6 months if not excised
Pharmacological
- No drug treatment is needed; oral contraceptives do not cause or worsen fibroadenomas
Surgical and interventional
Indications for excision
- Size over 3 cm (some units use 4 cm)
- Growing on serial imaging, or a giant or juvenile fibroadenoma distorting the breast
- Uncertain or atypical findings on imaging or core biopsy
- Suspected phyllodes tumour
- Patient anxiety or preference
- Onset after 35–40 years
Options
- Excision through a periareolar or inframammary (Gaillard Thomas) incision placed for cosmesis, enucleating within its capsule
- Vacuum-assisted excision under ultrasound for lumps under about 3 cm — no scar on the breast surface
- Wide local excision with a 1 cm margin for a phyllodes tumour
Complications and follow-up
- Haematoma, infection, dimpling or a scar from excision
- Recurrence at the same site (uncommon) or new fibroadenomas elsewhere (common in young women)
- Misdiagnosis of a phyllodes tumour
- Very rarely, carcinoma (usually lobular carcinoma in situ) arising within the fibroadenoma
No routine follow-up is needed after excision of a simple fibroadenoma with benign histology. Observed lumps are reviewed with ultrasound at 6 months.
Examiner questions
References
- O'Connell PR, McCaskie AW, Sayers RD, eds. Bailey & Love's Short Practice of Surgery. 28th ed. Boca Raton: CRC Press; 2023.