Pathology Of Breast Cancer
  • Based on conventional light microscopic evaluation
    • With use of hematoxylin and Eosin

Classification

  • Non-invasive ( in situ )
    • Presence of malignant epithelial cells that proliferate and fill the ductules and lobular acini
    • BUT there is no invasion of basement membrane
    • DCIS ( 85% )
      • Usually calcification in mammogram without palpable mass
      • If it's palpable there is a higher chance to develop to invasive Ca ( ?? )
    • LCIS ( 15% )
      • Calcification is rare
      • Usually incidental
      • Mammo negative
      • Multifocal and bilateral
      • 1-2% risk of breast ca development
      • 30-40% life time risk
      • A marker for increased risk for development of bilateral breast ca
  • Invasive
    • Ductal (65-80% )
      • Usually with DCIS
      • Prognostic Factors
        • Size
        • Lymphadenopathy
        • Grade
        • LVI
    • Lobular (5-10%)
      • Mutation of E-Cadherin molecule ⇒ dyshesive growth pattern
      • In mammogram → asymmetry in density of breast tissue; calcification is rare
      • Diffuse, size is underestimated → MRI better
      • Indistinct margins
      • Increase risk of bilaterality
      • LN mets happens quietly!
      • Usually ER PR +
      • Mets to unusual sites
        • Peritoneum
        • Meninges
      • Indian file pattern
      • flickr:5636465876
      • flickr:5635884815
    • Tubulolubular
      • Co-existent of tubular and lobular in a single invasive pattern
      • Some consider this as Lobular
    • Mucinous = Colloid ( 2% ) * Advanced age
      • Extracellular mucin visible in macro and micro samples
      • Favourable prognosis
      • Less LN+
    • Medullary ( 5%)
      • Younger age
      • Mass with clear margin
        • Rounded very well circumscribed
      • Syncytial pattern
        • Poorly diff cells growing in larger sheets
        • Numerous mitosis
        • Florid lymphoblastic infiltrate
    • Papillary
      • Better prognosis than ductal
      • Frond like papillary growth pattern
      • May have solid-cystic component
    • Tubular ( 1-2% )
      • Best differentiated form of ductal
      • Small- <1cm
      • Better prognosis
      • Less LN+
      • Grow as small acinar structures and tubules
      • Like normal breast tissue
    • Inflammatory
      • Aggressive
      • Diffuse breast enlargement
      • Inflammation + induration
    • Secretory ( juvenile )
      • Younger age even children! ☹
      • Abundant alpha-Lactalbumin
    • Adenoid cystic
    • Glandular ( adenoid )
    • Cystic ( cylindromatous )
    • Metaplastic
      • Differentiation along lines to tissues not usually seen in breast
        • Bone
        • Cartilage
        • Squamous cells
        • Undiff spindle cells
        • → pseudosarcoma
        • Usually ER/PR NEG
Favourable Pathology:
  • tubular carcinoma
  • mucinous carcinoma
  • medullary carcinoma