Updated: 11/14/2021

Malignant Breast Tumors

Review Topic
  • Epidemiology
    • breast cancer is the most common cancer and second most common cause of death in adult women
  • Risk factors
    • BRCA1 and BRCA2 mutations
      • associated with multiple / early onset breast and ovarian cancer
      • other genetic relationships
        • RAS oncogene gain of function
        • overexpression of estrogen/progesterone receptors
        • overexpression of erb-B2 (HER-2, an EGF receptor)
        • Li-Fraumeni associated TP53 loss
    • increasing age
    • smoking
    • breast cancer in first degree relatives or mother with breast cancer
    • history of contralateral breast cancer
    • history of endometrial cancer
      • also an estrogen induced cancer
    • increased exposure to estrogen
      • obesity
      • nulliparity
      • early menarche (<11 y.o.)
      • late menopause (>50 y.o.)
      • late first pregnancy (>30 y.o.)
    • atypical ductal hyperplasia
  • Ductal carcinoma in situ (DCIS)
    • arises from progression of ductal hyperplasia
    • non-palpable mass 
      • seen most often on mammography due to microcalcifications
    • histology shows filled ductal lumen without basement membrane penetration
    • subtypes
      • comedocarcinoma
        • ductal carcinoma with caseous necrosis at the mass center 
  • Paget's disease
    • extension of DCIS into lactiferous ducts and skin of nipple
      • eczematous patches on nipple 
    • histology shows Paget cells 
      • large cells in epidermis with clear halo 
      • also seen on vulva
  • Invasive/infiltrating ductal carcinoma 
    • worst and most invasive
    • most common type
    • firm, fibrous, "rock-hard" mass
    • histology shows small, glandular, duct-like cells with stellate morphology
    • subtypes
      • tubular carcinoma
        • histology
          • well-differentiated tubules that lack myoepithelial cells
      • mucinous carcinoma
        • histology
          • carcinoma with abundant extracellular mucin
  • Lobular carcinoma in situ (LCIS)
    • non-palpable mass
    • often bilateral
    • histology shows distended lobules with neoplastic cells without BM penetration
  • Invasive lobular
    • often multiple and bilateral
    • histology shows orderly row of cells
  • Medullary
    • associated with BRCA1 and ER/PR negativity
    • histology shows fleshy, cellular, lymphatic infiltrate
  • Inflammatory 
    • poor prognosis (50% survival at 5 years)
    • histology shows dermal lymphatic invasion by tumor
    • peau d'orange seen on exam
      • see below
  • Symptoms
    • often asymptomatic
    • breast lump
      • most commonly in upper-outer quadrant
    • nipple discharge
  • Physical exam
    • firm immobile, painless lump
    • some skin changes 
      • redness, ulcerations, edema, and nodularity
    • axillary lymphadenopathy
      • in more advanced cases
    • breast skin edema with dimpling (peau d' orange)
      • represents obstruction of the lymphatics by cancer  
  • Fine needle aspiration
    • can identify whether mass is solid or cystic
    • can also retrieve sample for cancer diagnosis
  • Estrogen/Progesterone receptor assays
    • most often positive in post-menopausal cancers
      • low estrogen state after menopause results in upregulation of receptors
    • positivity confers better prognosis with more effective therapeutics
  • Sentinel lymph node biopsy
    • if negative high likelihood no other nodes in group are involved
    • if positive there is 1/3 chance other nodes in group are involved
  • Surgery
    • breast conservation resection
      • resection of tumor with margins
      • sentinel node biopsy
      • radiation
    • modified radical mastectomy
      • resection of nipple, entire breast, pectoralis minor, and level I-II axillary nodes
      • level III axillary nodes removed if involved
      • complications
        • long thoracic nerve damage
          • results in winged scapula 
        • lymphedema
Prognosis, Prevention, and Complications
  • Prognosis
    • lymph node involvement is the single most important prognostic factor
    • TNM staging
      • extranodal metastases has more significance than lymph node metastasis
  • Prevention
    • mammography
      • effective screening tool except in young woman
        • dense breast tissue in young woman interferes with specificity and sensitivity
        • most effective in postmenopausal patients because of less glandular breast
      • identifies microcalcifications or moderate sized masses
      • all woman > 40 should have mammograms

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(M1.ON.13.1) A 52-year-old female was found upon mammography to have branching calcifications in the right lower breast. Physical exam revealed a palpable nodularity in the same location. A tissue biopsy was taken from the lesion, and the pathology report diagnosed the lesion as comedocarcinoma. Which of the following histological findings is most likely present in the lesion?

QID: 101662

Orderly rows of cells surrounding lobules



Disordered glandular cells invading the ductal basement membrane



Extensive lymphocytic infiltrate



Halo cells in epidermal tissue



Pleomorphic cells surrounding areas of caseous necrosis



M 2 D

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Evidence (3)
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