Fibroadenoma of Breast

Fibroadenoma is the commonest benign breast tumour, composed of proliferating glandular (epithelial) and stromal elements.

• It occurs mostly in women aged 15 to 35 years (peak 20 to 30), more common in women of African ancestry; it can also occur in postmenopausal women taking hormone therapy.
• It is hormone sensitive: enlarges in pregnancy and lactation, regresses after menopause.
• Variants: simple, complex (cysts, sclerosing adenosis, epithelial calcification, papillary apocrine change), giant (above 5 cm) and juvenile.

Painless, firm, rubbery, smooth, well-defined, highly mobile ("breast mouse") lump, 1 to 3 cm, usually in the upper outer quadrant; multiple in 10 to 20 percent and bilateral in some.

• No skin changes, nipple discharge or axillary nodes.
• Differential diagnosis: phyllodes tumour (rapid growth, large), breast cyst, fibrocystic change, lipoma, galactocele, fat necrosis, intraductal papilloma, breast cancer, lymph node, hamartoma.
• Complications: pain from rapid growth, infarction (in pregnancy), cosmetic deformity, anxiety, rare malignant change in complex fibroadenoma (relative risk about 1.5 to 3).

Triple assessment: clinical examination, imaging and core needle biopsy.

• Ultrasound (women under 40): well-circumscribed oval hypoechoic mass, wider than tall, thin echogenic capsule, uniform internal echoes, lateral shadowing, posterior enhancement; mammography in women 40 years and above (smooth oval mass, coarse "popcorn" calcifications in older lesions).
• Core needle biopsy (14 to 16 gauge) confirms biphasic histology and excludes phyllodes tumour or malignancy; fine needle aspiration is acceptable where core biopsy is unavailable (cytology cannot reliably distinguish phyllodes).
• Excision biopsy in discordant results.

Supportive: reassurance, education that the lesion is benign; avoid unnecessary surgery.

Pharmacological: none effective; hormone therapy review (postmenopausal use); analgesia for pain (paracetamol 1 g every 6 hours).

Procedures

• Observation with clinical review and ultrasound at 6 and 12 months for biopsy-proven fibroadenomas below 3 cm in women under 40 years with concordant triple assessment (about 30 percent regress, 20 percent shrink and 50 percent stay unchanged).
• Surgical excision (lumpectomy through a periareolar or inframammary incision), or ultrasound guided vacuum-assisted excision, for: size above 3 to 4 cm, rapid growth (over 20 percent in 6 months), patient anxiety, symptoms, age above 35 years with growth, indeterminate or phyllodes-suspicious histology, and discordant imaging.
• Cryoablation (ultrasound guided) for fibroadenomas below 4 cm.
• Giant or juvenile fibroadenoma: complete excision with preservation of breast tissue.
• Excision of phyllodes tumours with wide margins (1 cm).

Special groups: adolescents (observation, excise if above 5 cm or growing), pregnancy (observe; may enlarge), postmenopausal women (excise new lesions after biopsy), BRCA carriers (low threshold).

Red flags: rapid enlargement, size above 5 cm, fixation, skin changes, axillary nodes, discordant biopsy, new mass at age above 40 years.

Follow-up: review at 6 and 12 months; annual clinical review; breast awareness and routine screening by age.