GenSurg.nz

Aberrations of Normal Breast Development and Involution

Section: Breast Curriculum: Curriculum, page 9

Definitions

  • Post-lactational involution
    • Breast undergoes massive cell death and tissue remodeling as it returns to the pre-pregnant state
  • Lobular involution
    • Breast epithelial tissue is gradually lost with aging

Fibrocystic Change

  • Definition
    • Fibrosis, Cystosis, Adenosis & Epitheliosis
    • Exaggeration of normal hormonal process
  • Incidence
    • 20-40 years
    • 40% of breast lumps are fibrocystic
    • 7% women may be symptomatic with cysts
  • Aetiology
    • ? Minor hormonal imbalances
    • Oestrogen > Progesterone, COC protective
  • Clinical Manifestations
    • Palpable/non-palpable lumps
    • Single or multiple (> bilateral)
    • Painful – usually sclerosing adenosis with trigger zone
    • Recurrent or fast-growing cysts
  • Ix:
    • Triple assessment if palpable or if other risk factors (e.g. FHx, age, bloody)
    • USS & mammogram
    • USS shows a solid component → USS-guided Bx
    • Atypical features (septations, irregular, solid component) → core / excise
  • Cysts aspirated:
    • If fluid blood-stained → Triple assessment
    • If any residual lumps → Triple assessment
    • Cyst fluid typically not sent for cytology as yield is very low and unreliable
  • Mx
    • If painful mass – Aspirate ± can excise; otherwise mastalgia advice
    • Recurrent cysts can be treated with repeat aspiration
    • If cyst resolves after aspiration (& screening up to date) reassure and discharge
    • Non-palpable cysts are not routinely drained radiologically
  • Natural Hx:
    • Variation of normal
    • 10% of cysts aspirated to dryness recur
    • 50% of pts with cysts will develop further cyst over 10 years
    • Follow-up 3 months

Fibrocystic Change - Fibrosis

  • Overgrowth of fibrous stroma
  • Often accompanied with cystic change
  • “Fibrocystic change”
  • ↑ fibrous stroma with duct dilatation & formation of cysts
  • ? may arise as a result of cyst rupture → Chronic inflammation → Fibrosis

Fibrocystic Change - Cystosis

  • Cyst = Fluid filled cavity lined by epithelial cells
  • Cystic involution of the breast lobule (Apocrine)
    • Outflow obstruction due to epithelial hyperplasia / stricture or fibrosis of terminal ductules / kinking of ducts + secretion by distal lobule → Cyst
    • Lobules develop microcysts → coalesce into larger cysts
  • Characteristic halos on mammography
    • USS essential
      • Can distinguish solid and cystic lesions
      • Also give info on septations and differentiate simple and complex cysts
  • Simple Breast Cysts
    • No association with cancer
    • Lined by simple cuboidal epithelium
    • Classic USS features meaning likely benign
      • Wall calcified
      • Mobile particles (usually cholesterol crystals)
  • Complex Breast Cysts
    • Possible association with cancer
    • Lined by apocrine epithelium (apocrine metaplasia) with columnar cells
    • High K:Na ratio
    • Tend to recur

Cancer risk ↑ed (estimated >2%) if:

  • Blood in cyst
  • Lump present after aspiration
  • Thickened walls
  • Thick (> 2mm) internal septations
  • Mix of cystic & solid components
  • Co-existent Florid ductal hyperplasia

Fibrocystic Change - Adenosis

  • Increase in number of lobular acini / glandular elements
  • Cells & basement membrane have normal relationship
  • 3 types:
    • Sclerosing adenosis
      • Proliferation of terminal duct lobules (enlargement & distortion)
      • ↑ no. of acini + fibrous stromal ∆ with intralobular fibrosis
      • ± Associated with microcalcifications
      • Differentiated from Radial Scars (RS)/ Complex Sclerosing Lesion (CSL) by degree of excessive myoepithelial proliferation seen in RS and CSL
      • Mx - Nil
    • Radial Scar (< 1cm)
    • Complex Sclerosing Lesion (> 1cm)
      • Background for development of atypical epithelial proliferations including ADH (Atypical Ductal Hyperplasia) and DCIS
      • Increased risk of malignancy
      • Difficult to distinguish from malignancy – associated with malignancy ~ 10%
      • Mx - Open excision recommended

Fibrocystic Change – Epithelial Hyperplasia

  • Usually incidental finding
  • Proliferation of epithelial cells in ducts or lobules with ≥ 3 layers of cells
  • Normal = 2 cell layers (epithelial & myoepithelial)
  • Hyperplasia: ↑ed no. of layers ± ‘fenestrations’ within layers
  • Classification: Ductal vs. Lobular ± Atypia
  • Path: extent of hyperplasia:

RR of Cancer:

Graph View

Backlinks