DCIS


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  • Clinical

    • 20-25% of breast cancers
    • most detected by imaging (calcifications), but can be a palpable mass
    • DCIS is associated with undetected or future invasive cancer
    • prognosis
      • size, nuclear grade, comedo necrosis, margin status
      • hormone: ER+ treated with tamoxifen. PR controversial.

  • Histology

    • nuclear grades
      • low
        • small monomorphic cells, even distribution (non-overlapping), good luminal polarization
        • rare mitosis, inconspicuous nucleoli, even chromatin, uncommon necrosis
        • patterns: bridge archs, micropapillary, cribriform, solid
      • intermediate
        • mild to moderate cell variability
        • can have mitosis, necrosis, coarse chromatin, variable nucleoli
      • high grade
        • overt pleomorphism
        • common mitosis, prominent nucleoli, clumpy chromatin, comedo necrosis
        • patterns: solid, cribriform, micropapillary
    • traditional subtypes
      • solid
      • cribriform
      • papillary
      • micropapillary
      • comedo type necrosis: comedo necrosis, but low grade
      • comedo DCIS: high grade with comedo necrosis
    • microinvasion: 1 mm extension through myoepithelial layer

  • Stains

    • myoepithelial markers+ (vs loss in invasive carcinoma)
      • smooth muscle myosin
      • p63
    • CK5/6 negative (vs UDH positive)
    • E-cadherin+ (vs lobular negative)
    • ER (75-80%), PR (lower), positive is >= 1% of cells
    • HER2 not as useful because it's frequently overexpressed in DCIS

  • Grading

    • low grade: monomorphic uniform cells
    • intermediate grade: in between
    • high grade: ugly cells

  • Ddx

    • UDH with necrosis
    • ADH
    • florid or pleomorphic LCIS

  • Sign out

    • DCIS, ___ grade, ___ pattern
    • on excisions: size, margin
    • no invasive carcinoma
    • microinvasion on bx requires sentinel lymph node
    • give ER/PR status
    		•