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Benign Breast Conditions

This article should be read in conjunction with the breast cancer article.

Benign Breast Tumours

The suspected breast cancer referral pathway also applies to benign breast tumours

Refer via the suspected breast cancer pathway if:
  • ≥30 y/o + unexplained breast lump, or
  • ≥50 y/o + unilateral nipple discharge / retraction / other changes of concern
CONSIDER refer via suspected breast cancer pathway if:
  • Skin changes suggest breast cancer, or
  • ≥30 y/o + unexplained lump in the axilla
Consider non-urgent referral if:
  • <30 y/o unexplained breast lump

Fibroadenoma

Definition

Fibroadenoma is a benign breast tumour characterised by a biphasic proliferation of stromal and epithelial components

Aetiology

The exact cause is incompletely understood and is considered multifactorial

 

Current evidence suggests that fibroadenomas arise from a hormone-driven process, with a role for oestrogen sensitivity and genetic mutations

Diagnosis – Triple Assessment

Fibroadenoma is the most common benign breast tumour in <25 y/o [Ref]

  • Peak incidence: 20-30 y/o
  • Risk is highest in <35 y/o and declines after menopause
Triple assessment component Findings / description [Ref1][Ref2]
Clinical examination
  • Most commonly solitary
  • Well-circumscribedmobile, non-tender breast mass with a rubbery consistency
  • Usually 1-3 cm (only ~20% cases are >4cm)
  • Slow growth

The term “breast mouse” is sometimes used to describe the typical feel and mobility of a fibroadenoma in palpation. The mass is highly mobile, such that on palpation it seems to slip away / move under the fingers, like a mouse running under the skin

Imaging Ultrasound is typically 1st line (as fibroadenoma is rare in >40 y/o) (rule of imaging for breast mass)
  • Ultrasound finding: well-defined, oval, hypoechoic or isoechoic mass
  • Mammogram finding: sharply circumscribed, homogenous round / oval mass
Biopsy Gold standard: core needle biopsy
  • Diagnostic findings: biphasic proliferation of stromal and epithelial elements
  • The lesion is sharply demarcated from the surrounding tissue
  • No atypia, and low mitotic activity

Complications

Malignant transformation of fibroadenoma is extremely rare (<0.1%) [Ref]

Management

Conservative management (reassurance + education + discharge) for biopsy-proven fibroadenoma without atypia. [Ref]

 

Excision is NOT routinely indicated. Some indications for excision: [Ref]

  • Patient’s request
  • Symptomatic (discomfort / pain)
  • Rapid growth
  • >4 cm may warrant excision to exclude a phyllodes tumour (it can be difficult to differentiate between a fibroadenoma and phyllodes tumour, even with biopsy) or other pathology
  • Radiological / pathological discordance

Phyllodes Tumour

Definition

Phyllodes tumour is characterised by a biphasic proliferation of neoplastic stromal and non-neoplastic epithelial components

 

Importantly, phyllodes tumour can be either benign (more common) or malignant (it is not a 100% benign tumour)

Phyllodes tumours and fibroadenomas have similar clinical and histological features (both are fibroepithelial neoplasms.) It is difficult to distinguish between a phyllodes tumour and a fibroadenoma, even with a biopsy.

Importantly, phyllodes tumour has the potential for recurrence or malignancy

Diagnosis – Triple Assessment

Most common in 35-55 y/o [Ref]

Triple assessment component Findings / description [Ref]
Clinical examination
  • Rapidly growing mass
  • Often >3-5 cm
  • Well-circumscribed, firm and mobile breast mass
Imaging Rule of imaging for breast mass
  • Ultrasound finding: lobulated margins, heterogeneous hypoechoic internal echoes
  • Mammogram finding: high-density, well-defined mass, sometimes with lobulated contours
Biopsy Gold standard: core needle biopsy
  • Biphasic proliferation of stromal and epithelial elements
    • Marked stromal hypercellularity, increased stromal mitotic activity
    • The epithelial component may show fronded or leaf-like architecture
  • Depending on histological findings, phyllodeous tumour can be classified into benign, borderline or malignant

Both phyllodeous tumour and fibroadenoma present with a well-circumscribed, mobile breast mass which can be difficult to distinguish both clinically and histologically.

Typical factors that are helpful for exams:

  • Phyllodes tumour is more likely in older women, with larger, rapidly growing masses
  • Fibroadenoma is more common in younger women, with smaller, stable masses 

Complications

The most important complications associated with benign phyllodes tumour are local recurrence and, in malignant casesdistant metastasis

Management

Surgical excision is the cornerstone of management for ALL phyllodes tumours (due to risk of recurrence / distant metastasis) [Ref]

Intraductal Papilloma

Definition

Intraductal papilloma is a benign breast tumour that arises from the epithelium of the lactiferous ducts

Diagnosis – Triple Assessment

Intraductal papilloma is relatively uncommon, accounting for ~4-5% of breast biopsies [Ref]

  • Median age of diagnosis: 50-60 y/o [Ref]
Triple assessment component Findings / description [Ref]
Clinical examination
  • Palpable mass near the subareolar region
  • Bloody nipple discharge (seen in 1/3 cases)
Imaging Rule of imaging for breast mass
  • Ultrasound findings: well-defined, smooth-walled, solid hypoechoic nodule, often accompanied by ductal dilatation and visible intraluminal echoes
  • Mammogram findings: smooth, well-circumscribed mass
Biopsy Gold standard: core needle biopsy
  • Diagnostic findings: papillary proliferation with a fibrovascular core lined by both luminal epithelial cells and myoepithelial cells

Management

All intraductal papilloma with atypia (biopsy-proven) should be excised (due to risk of associated malignancy) [Ref]

 

Surgical excision is NOT routinely indicated for intraductal papilloma without atypia [Ref]

  • A common indication for excision is troublesome symptoms

Other Benign Breast Conditions

Note that mastitis and breast abscess are also important benign breast conditions, but are covered in a separate article.

Condition Presentation Management
Fibrocytic breast disease Most common type of benign breast condition

 

Clinical features:

  • Bilateral pre-menstrual breast pain (cyclic mastalgia)
  • Bilateral ‘lumpy’ breasts (from breast masses)

 

Ultrasound findings:

  • Scattered calcifications
  • Clustered microcysts
Conservative management for most patients

 

Surgical excision is necessary for those with atypia (e.g. atypical ductal hyperplasia)

Breast cyst Most common in peri-menopausal women
  • Single / multiple breast masses
  • Smooth, soft and firm texture
  • Usually mobile
  • Maybe tender

 

Ultrasound is used to differentiate between cystic and solid breast masses

  • A biopsy is necessary for cysts with suspicious features (e.g. solid component, Doppler flow)
A simple breast cyst doesn’t need any specific management
  • Ultrasound-guided fine needle aspiration can be used to manage symptomatic cysts

 

Complicated / complex breast cysts needs surveillance +/- excision (due to risk of malignncy)

Galactocele Galactoceles are cysts that form from milk retention during lactation

 

Presents as a firm mass in the subareolar region that typically occurs after lactation

A galactocele doesn’t need any specific management
  • Fine needle aspiration / drainage catheter can be used to manage symptomatic ones
Fat necrosis of the breast Typically occurs after breast trauma / surgery / radiation

 

Presents as a poorly defined breast mass with irregular borders (may mimic breast cancer)

 

Imaging +/- biopsy is often necessary to exclude malignancy

Fat necrosis doesn’t need any specific management if magliancny is excluded by biopsy
Mammary duct ectasia Most common in peri-menopausal women

 

Typical presentation:

  • Green / milky nipple discharge
  • Nipple inversion
  • A tender subareolar mass may be present
Mammary duct ectasia doesn’t need any specific management

 

Consider surgical duct excision in those with persistent symptoms / nipple discharge

Mondor’s disease of the breast This is superficial thrombophlebitis of the breast
  • Sudden onset, painful thickened cord-like lesions
  • Overlying redness
Conservative management

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