Morphology of infiltrating duct carcinoma

MORPHOLOGY OF INFILTRATING DUCT CARCINOMA
Gross:
  • Tumor presents as hard,irregular mass associated with desmoplastic stromal reaction.
  • Some of the tumors are gritty due to foci of calcifications and desmoplastic stroma
  • Rarely they present as circumscribed tumors
  • Larger tumors infiltrate deeper structure like pectoralis muscle or may ulcerate on surface
  • If the tumor is present in the central portion of breast then the retraction of nipple develop.
  • Peau d’orange develops in inflammatory carcinoma. It is caused by cutaneous lymphatic obstruction causing edema, which leads to swelling but the infiltrated skin is tethered by the ligament of Cooper such that it cannot swell, producing an orange skin like texture with dimpled appearance
Microscopy:
  • Tumor cells are arranged in glandular pattern, sheets, cords, cribriform pattern.
  • Tumor cells infiltrate into the fibro fatty stroma.
  • vascular, lymphatic invasion and perineural invasion may be present
  • Nuclear pleomorpism & atypical mitotic figures are seen.
  • Depending upon the tubule formation,nuclear pleomorpism & mitotic rate,tumors are graded according to Nottingham histologic score.
  • Histologic grade Nottingham histologic grade depending upon nuclear grade, tubule formation and mitotic rate is an important prognostic factor. Depending upon these factors 3 histologic grades have been described. Grade 1 is well differentiated and grade 3 is poorly differentiated.
    • Tubule formation –
      • 1 point – >75% of tumor
      • 2 points- 10 – 75% of tumor
      • 3 points – <10% of tumor
    • Mitotic figures
    • Nuclear pleomorphism
      • 1 point – minimal nuclear variation in size and shape
      • 2points – moderate nuclear variation in size and shape
      • 3 points – marked variation in size and shape
    • Scoring
      • 3 – 5 points – well differentiated (grade I)
      • 6 – 7 points – Moderately differentiated (grade II)
      • 8 – 9 points – poorly differentiated (grade III)
  • Morphological features in molecular subtypes of ductal carcinoma:
    • ER positive,HER2 negative carcinoma
      • Graded well to poorly differentaiated
      • Morphologic patterns-mucinous ,papillary, cribriform & lobular pattern.
    • HER 2 positive carcinoma
      • Grade-poorly differentiated carcinoma
      • Morphologic pattern –Apocrine (50%) & micro papillary (40%)
      • Associated DCIS is more extensive.
    • ER-negative.HER2 negative carcinoma
      • Grade poorly differentiated
      • Morphologic pattern-Tumors have pushing borders with central necrosis
      • Tumor has medullary features with peripheral lymphocyte infiltrate.
      • Spindle cells squamous & matrix producing patterns can be seen.
      • DCIS is limited as absent.
References
  1. Vinay kumar, Abul K.Abbas, Nelson Fausto, Jon C. Aster. The Breast. In: Robbins and Cotran Pathologic basis of disease. 8th edition.