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Breast Surgery

Fibroadenoma

A benign fibroepithelial breast lesion, usually presenting in adolescents or young adults as a smooth, firm, mobile lump; diagnosis depends on concordant clinical and imaging assessment, with biopsy or excision when the pattern is atypical.

In a nutshell

Fibroadenoma is a benign fibroepithelial breast lesion, usually a smooth, firm, mobile lump in an adolescent or young adult. Use the age- and feature-appropriate breast assessment pathway: a classic lesion under 25 may not need biopsy, but enlarging, large, complex, atypical or discordant lesions need tissue or specialist review. Confirmed asymptomatic fibroadenomas usually need reassurance rather than surgery; the key safety differential is phyllodes tumour.

Classic presentation

An adolescent or young adult has a smooth, firm, painless, highly mobile breast lump with normal skin, nipple and axillary examination.

Key points

  • A fibroadenoma is a benign biphasic fibroepithelial lesion and may enlarge during pregnancy or other hormonal states.
  • NICE NG12: suspected cancer referral for an unexplained breast lump at age 30 or over; consider non-urgent referral under age 30, with clinical judgement for suspicious features.
  • Under 25, a classic fibroadenoma may not need biopsy if clinical and ultrasound findings are confidently concordant.
  • Large, rapidly growing, complex, atypical or discordant lesions need core biopsy, specialist MDT review or excision.
  • Most confirmed asymptomatic fibroadenomas need no treatment or routine follow-up.
  • Vacuum-assisted excision or open excision can be considered for selected symptomatic, giant, complex or patient-preferred lesions.
  • A rapidly growing fibroepithelial mass may be a phyllodes tumour; do not provide routine fibroadenoma reassurance until the diagnosis is secure.

First-line investigation

Age-appropriate breast assessment, usually ultrasound in younger people, with core biopsy when the lesion is atypical, growing, large or discordant.

Management

Identify suspicious breast features

  • Use the current breast referral pathway for an unexplained lump; expedite assessment for rapid growth, skin or nipple change, axillary nodes, older age, previous breast cancer or clinical and imaging discordance.3,4

Confirm concordant benignity

  • Use age-appropriate imaging, usually ultrasound in younger people, and add core biopsy when the lesion is atypical, growing, large, complex or uncertain; a classic under-25 lesion may not require biopsy if assessment is confidently concordant.1,2

Reassure and safety-net

  • Most confirmed asymptomatic fibroadenomas need no treatment or routine follow-up; advise return for growth, new pain, altered character, nipple or skin change or an axillary lump.1,2

Remove or reclassify selected lesions

  • Consider vacuum-assisted or open excision for giant, complex, symptomatic, cosmetically troublesome or patient-preferred lesions; refer indeterminate fibroepithelial lesions for MDT review and possible excision as phyllodes tumour.1,5,4

Review change rather than schedule routine surveillance

  • Do not arrange routine follow-up for an uncomplicated confirmed asymptomatic fibroadenoma unless the breast team advises otherwise; reassess any new or changing breast symptom and explain that complex fibroadenoma may carry a small increase in risk.2,4

Exam traps

  • Mobility is reassuring but does not replace appropriate breast assessment.
  • A classic lesion under 25 may not need biopsy, but a growing or atypical lesion does.
  • Do not label a rapidly enlarging fibroepithelial mass as a fibroadenoma without considering phyllodes tumour.
  • Do not excise every fibroadenoma; most confirmed asymptomatic lesions need no treatment.
  • A benign previous biopsy does not mean a later enlarging or changing lesion can be ignored.

Illustrations

Fibroadenoma on ultrasoundBreast ultrasound showing a well-defined oval mass with smooth margins, labelled as a benign-appearing feature that still requires clinical and imaging concordance.Nevit Dilmen (talk), Wikimedia Commons · CC-BY-SA-3.0
Fibroadenoma histologyHistology showing benign biphasic fibroepithelial architecture, with proliferating stroma around epithelial-lined ducts.Department of Pathology, Calicut Medical College, Wikimedia Commons · CC-BY-SA-4.0

Key sources

  1. NICE HTG449: High-intensity focused ultrasound for symptomatic breast fibroadenoma (NICE health technology guidance summarising diagnosis and treatment options for fibroadenoma, including conservative management, surgery and vacuum-assisted removal; published 13 September 2017.)Updated 13 Sept 2017
  2. NHS: Fibroadenoma (NHS information on diagnosis, age-related ultrasound and biopsy use, conservative management, excision, vacuum-assisted excision and follow-up; page last reviewed January 2024.)Updated 1 Jan 2024
  3. NICE NG12: Suspected cancer: recognition and referral (Current NICE breast referral thresholds for unexplained breast lumps, nipple and skin changes and axillary lumps; last updated 15 April 2026.)Updated 15 Apr 2026
  4. Breast Cancer Now: Fibroadenoma (UK patient information on features, diagnostic biopsy, benign and complex fibroadenoma, phyllodes tumour safety-netting and treatment choices; 2025 edition.)Updated 1 Jan 2025
  5. NICE HTG80: Interstitial laser therapy for fibroadenomas of the breast (NICE health technology guidance describing conservative management and surgical or minimally invasive removal when fibroadenomas persist, grow or cause concern; published 22 June 2005.)Updated 22 Jun 2005

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.